Witchipedia

It can be very difficult sometimes to let go of the past, especially when others keep reminding you of it. It is important to remember two things: First, you can't control other people, you can only control yourself. And second, other people only have the power over you that you grant them.

That being said, it can still be very difficult to control your emotional response to things and people in your environment, especially when you have been bombarded by negativity and have developed negative thought patterns over a long period of time. Negativity becomes a habit, an addiction even, and may need to be treated like one. You have to take charge of the situation and let people know you're doing it. Stand up for yourself while still being respectful to others. Let people know your feelings without being aggressive. Say "This conversation is making me uncomfortable/is hurtful to me, I would prefer to end it now." and if the other person refuses, leave.

I am a strong believer in counseling because I feel it is important to release bottled up feelings through talk and it's not always appropriate to give them to friends and family members. They may not be prepared to receive them, or may misunderstand your intent in sharing them and this can damage the relationship. While I do feel it's important to let people know when they are hurting you (and when they make you happy), it's not a good idea to keep bringing things up from the past that have already been addressed. If these things are troubling you, a neutral party to talk to is a good idea. If cost is a factor, contact your local University and see if they have a counseling program. Some schools have programs that allow students to counsel people for very little cost (like $5-10) or even free. And really, you just need to talk to someone, you're not looking for medication, so who cares if they lack experience.

I also believe that meditation helps us greatly in finding a middle ground in our emotions. It helps us understand our thoughts by giving us a quiet place to reflect on them without judgement and also strengthens our own psyches, allowing us to resist the negativity of others. Yoga is also very helpful in this regard; it is like a moving meditation.

Pathworking is extremely helpful for some people and it is a discipline that can only improve your magickal skills and insight, so definitely give it a try. http://www.pathworking.com is a good place to start.

Please also don't discount the power of prayer. If you have Gods, by all means talk to them. Often. And if you don't, perhaps there are some ancestors you'd like to talk to.

There are also several spells and rituals that can be very helpful. Try a cleansing ritual bath to remove the negativity and then shield yourself from further negativity. Repeat often. (See also How do I protect myself from curses)

Basil oil encourages family harmony. I like to put it in my wash water when I do the floors to fill the home with its fragrance, especially when difficult company is coming over. Keeping a plant our two around the house is also helpful.

Finally, smile. Smiling really does make you feel better. So smile big and let the love in your heart shine!

If negative feelings are projecting outwards, you are probably feeling quite tense and pressured on the inside. An angry reaction often comes from a place of defensiveness if you feel you are not in control of a situatiion.
Using the techniques morningbird mentiins above, try working on these two things- 1) changing your perception of control and 2) changing how you treat yourself.
1) control. Control issues generally relate to a fear of other people exercising control over you. Think before you speak. You don't have to "get your way' to remain in control. If something challenging happens, take a pause for a few seconds, and take a breath. Imagine how your "fantasy self" would effortlessly handle it in a positive way and react accordingly. Ask yourself " how is this other person feeling right now? It might be helpful to us both if i diffuse this " " do they have a point i can gracefully acknowledge?" " what is more important right now - being 'right' or maintaining harmony?" That's not to say that you should always concede, but it's fine to say " i disagree, but let's not fall out". Try and nourish a curiosity about other people "in the moment" and, putting aside your feelings for a few seconds and using your best witchy self, really "see" them. This will help foster compasdion and help you to handle other people in a way that is positive and makes you feel good about it. No-one notices a pause of three seconds or so, which is all it will take to do this processing once you get the hang of it.
Also, think on this - short of kidnapping you or using violence (in which case get the hell out) no one can.control you. If someone tries to manipulate you into something you don't want to do, a ready-made firm excuse is fine, and a more skillful handling is to say "no thanks, i don't enjoy that sort of thing," or "i don't have time" a polite decline at an early juncture is way better than the disappointment and potential for conflict if you let someone down later. If someone nags persistently you can just smile and say "no, sorry". These days, if my sister in law is daft enough to ask me to go on a shopping trip wjth her, i just say "hell no! I hate shopping!" And we laugh. "I really don't fancy doing that, but you go and enjoy yourself" is also an acceptable answer. If you're letting someone down who is asking for help, just give an honest reason and it's fine to say "i'm sorry, i can't as i'm exhausted" or whatever.
If you give in because you're exhausted after someone whines at you persistently, they will know that you can eventually be persuaded with persistence. Instead, feel free to give a friendly chuckle and say "oh bless you, you're still asking" before shaking your head and walking away with a look of sympathy.
2) how you treat yourself. After all this liberating handling of other people, you are probably already feeling a lot more confident. Build on this. Say to yourself "what can i do to best take care of myself in this moment?" And get that coffee, take that walk, ring that friend - do a small thing that will nourush your body and soul most in that moment. Remind yourself that you're taking good care of yourself. Being kind to yourself works wonders on your attitude. Take it further, foster kindness to other people. Small things - smile at people, chat in the lift, be courteous, chat to the old lady on the.bus if she starts talking to you. Be patient with the elderly person ahead in the queue who just won't stop talking to the cashier - it might be the only human contact they get all day. Be loving whilst maintaining the boundaries set in 1) above and you will realuse your attitude is "tip top" and you feel.better. Uf you change your attitude to yourself in this way, you will find that ither low level "bad attitudes" to food, motivation etc also fall into place.

Use the techniques mentioned by morning bird and, in terms of meditation try mindfulness. It will help you to foster all of the above. Look up Jon Kabat-Zinn on youtube. That man saved my life. Blessings.