How to get out off bootloop?

If you're able to get to recovery mode, maybe you can flash a stock rom or use a backup. You may also be able to use ADB to flash a working rom, this tutorial is for the htc one but it's mostly the same.

You can also just keep turning it on I guess, I've gotten lucky plenty of times when a phone that was seemingly bricked and not exiting a bootloop just decided to work one day.

Also, if you are having issues flashing roms to your phone you should probably do a bit more research. Using reliable cables, not turning off devices and doing a bit of research into other people who were able to successfully flash and those who unsuccessfully flashed to a device is always a good way to prevent these mishaps as well as fix them. This tutorial explains the process quite well.