My iPod 5th gen seems like it is beginning to fail. What can I do to fix it or should I just give up and buy a new one?

A few days ago the home button suddenly started getting a little stiff when pushing and I began using the assistive touch to avoid further damage to the home button. Eventually mistakes were made and the home button became lodged and unusable. I should probably mention that I don't have applecare and I purchased the iPod two years ago. Battery life has also gone down the drain to where I need to plug it in at least 3 time a day. I've always had a problem with charging items too much so that's my fault. Another problem began just yesterday, for some strange reason I was unable to play videos or music and kept getting an error message. Any audio or video was just impossible to play, so I looked up quick fixes and tried them. They still did not work so I gave up, shut off my iPod for the night and decided I'd try fixing things today. Currently, I have turned it on and video and audio seem to be playing perfectly. I do not know how it's fixed itself but it has although I'm pretty sure the problem is going to come back soon. What can I do to fix it? How much would it cost at an apple store or am I better off buying a new one?