Not only is malware written with bad intent, but it is often written badly. It can leave a mark on your computer’s performance even after it’s been removed.
Malware is just software. It doesn’t destroy your computer hardware in any way. Some work, albeit perhaps significant work, will get you back up and running without needing to destroy anything.
There are many reasons a computer might get stuck continually rebooting. Fortunately there’s no need to lose data. You have several ways to get your data off there and with a little bit of luck you may get you a working system again as well.