Like Jullianna, I too look back on all that God has done for me....and is still doing.
Also, if you're feeling down in the dumps, look for someone to help. Even if you're doing the smallest thing for them. I find I feel much more fulfilled if I know I'm doing something for someone. It actually helps me stay on track. It makes perfect sense considering Jesus spoke of the two greatest commandments as being..
1) Love God
2) Love people
Also, I'd just say to remember to never base your relationship with God on what you feel or don't feel. Feelings are fleeting. His love is eternal.
I'll say a prayer for you. This will pass.