HELP!!!

OK those who know what I'm talking about will know, those who don't will have a rough idea but trust me you won't be able to figure it out. But either way please do just tag and leave me your advise.

Well I've had this stupid black cloud lingering over me for years now. I've kept this deep dark secret from loads of people. One of whom is "HIM". He is so important to me yet I've kept this from him. I know I should tell him but I just don't seem to be able to. I guess its cause I'm afraid of his reaction to the news. I don't want to lose him, but I know if I don't tell him it'll only get worst. But on the other hand if I do tell him he might get pissed at me from keeping it from him all these years. Arrggh! I'm so confused. I seriously need help on this issue people. Please do help. Please give me your suggestions on whether I should tell him or not. If yes, please state how. I really need all the help I can get you guys.