I can't sign into my apple account, or download anything.

I Cant download anything on AppStore. it asks for my password, and then it begins downloading and just stops And asks for my padsword again. I've tried restarting my phone, I've tried deleting apps incase it needed space or something, I've tried logging out and logging back into my apple account, but now it won't even let me log in. It's not because of my password being typed in wrong because it starts downloading and just stops, and I also tried resetting my password. it doesn't even come up with a message. Please help its bugging me so bad