I think I've figured out the issue. My solid state drive seems to have given out on me.
I plugged my previous platter-based hard drive back in, and, although super slow by comparison, it has yet to give me the same weird crashes that the SSD was. Definitely gonna have this sent in for a replacement -- they're so pricey right now. *grumble grumble*
I'll hopefully be up and posting again by tomorrow night. Thanks for your patience.