Orgasms/Depression

I don't know why, but when I'm depressed, I can't seem to get horny! People that I know of don't know the answer to why I can't. Sometimes I try to play with myself when I'm depressed it just doesn't work out. But when I try my hardest, when I do cum, its not that usual amazing feeling you get. Its pretty shitty. Is this normal?? Because I know a lot of people who can get horny right off the bat after being sad or depressed...and it usually cheers them up...but for me, it doesn't. Sorry for the kinda dumb question... I have just been wondering this for a long time.