The thing with problems (especially emotional problems) is that at some point you loose sight of the cause and concentrate on the hate/dissappointment/sadness. You get angry at the fact that you are angry and there starts the downward spiral.
A conselor will help you get that cloudliness away and make you face the real cause of your problems. Once the cause identified he will give you tools for you to heal. Then it's all up to you to use them and stick with it. It's not an easy road but it beats being sad and angry all the time.
You have to change what can be changed and accept what cannot. There's no shame in saying you need help and like others have said it will probably make you stronger and I bet it will make you happier.
Life's hard sometimes and reading your post make it apparent that you had your load. I guess it's time you get a break.
And one last thing dude, if seen someone makes you angry then it's up to you to not see that person anymore. It's often better to walk away. Your not letting them win, your giving yourself a chance to regroup.