iphone takes long to recover

Hello,

So my iPhone 7 plus is now in recovery mode (IOS 11.3). It takes hours and nothing is happening. I am now in DFU mode and still noting is happening. before I got my iPhone in recovery mode it was glitching, getting way to warm, apps were closing and my iPhone kept rebooting. Does anyone have any idea what I can do? Or how long it supposed to take?

Thanks!