My watch has been charging all night, but it won't turn on.

My watch has been charging all night, but it won't turn on. It is hot, so I know it's been charging, but I pressed the side button and the crown to try and restart it, but the apple logo shows and then it turns back off. I haven't used it in a while (a couple months), but it has been in a drawer, so I know that it wasn't damaged. What do I do?