My Phone overheated and now it isn't working right, what do i do?!?!

[AC Question]

Hi everyone, i'm really trying to avoid the options of getting a new phone or a battery replacement so I would really appreciate the feedback. My phone got really hot while charging and now it isn't charging properly, it will say it's dead and then minutes later it says its fully charged, when i try to turn it on it will only stay on for a couple seconds and then turn back off, I don't know whats going on or how to fix the problem. Any feedback on my problem would be helpful at this point, I'm really trying to avoid financial terms with the phone.