So this has been happening for a while now, I am running games and need to reset, so I reboot the core, or reload the rom, or even make a save state at the start of the game and just load that. But, every 2 or 3 times I do this (any of the methods) my bizhawk crashes. Anyone else experiencing this?

Are you using the most recent version? And what errors do you get when it crashes? You might want to report them if using the most recent version does not help: https://github.com/TASVideos/BizHawk/issues

Definitely make sure you are using the most up to date version. This is happening across multiple games as well (just for clarity)?

I had just reinstalled it on a new PC so it should be the newest version, and it happens with any game I play

Well...occasionally the latest and greatest could have some bug that your system really does not like. If you install the same version you had working before does it work? Also you should submit this as a ticket to them along with the errors you are getting which you failed to provide here.