Why do I do?

Well let's see I'm happy, sad, mad & confused all at the same time. I'm happy because "someone" cares. I'm sad because of my sin. I'm angry at my self for sinning. And I'm confused at how I could let past sins come back and take hold of me, so now I'm having a hard time fighting it like never before. It's one of those sins you hope nobody ever ever ever ever ever finds out about. It's really hard because whenever I tried to run to God and draw closer to Him, satan, the world and sin are fighting me harder than ever before, and I can't seem to break loose. I tell myself I won't sin, then I sin. I tell myself, I'm going to read my Bible, i don't read. I pray and struggle daily to get free. Why do I do what I don't want to do, and I don't do the things I know I really should do? Please pray that God would give me the strength to fight this, and that He would bring me back to Him.