If we look at a more primitive version of a Father-daughter/son relationship (our Earthly parents), most typically have unconditional love for their children. Now, lets look at a more perfected form of unconditional love in our relationship with our Heavenly Father. We know from numerous scriptures, one being John 3:16, that God loves us so much... Whatever sins you have committed, the Savior washes away when you accept Him and ask for forgiveness. This doesn't mean God rejoices when we sin, however, He rejoices when we turn to him. You forsaking your past actions is evidence of that. Even if you didn't forsake it, He would still love you... Kind of amazing if you really think about it.
As for why things somethings go south for you, I have no idea. I just know it's not because God "hates" you. I'm not even sure if it's really the Devil. It could be psychological. Either way, I think it would be very wise to speak to a professional (continually) and follow their advice... all while working on your personal relationship with the Lord of course.