How do I re-kindle my fire for God.

I've backslidden far and now, I don't care for sin nor despair over it, I don't feel the love of God nor his presence with me, forsaking him is easy now, and I just feel apathetic towards God. I'm getting closer again, I'm feeling the sadness over my sin, and his love is making me cry even just a tear again but, I'm still so apathetic towards God. Please help..