Why am i feeling this way?

Damn! i can't help it but i'm feeling shitty. My mind keeps on wondering about telling HER the truth but i daren't. I don't feel i have enough confidence to say it to her. Why? Can someone please tell me why? Damn i don't think you all will understand either. Well....... maybe you all bloggers out there can give an opinion on what should i do. Should i tell her the truth soon or wait till its the right time? I would gladly appreciate it. Thanks