Before Sunday, it was freezing up occasionally, but I thought nothing of it. Since Sunday, though, it has gotten extremely bad.
On Sunday, it would usually freeze up at various points during startup, but it would boot in safe mode, and I finally managed to get it to boot up and go through the login process.
On Monday, though, it got even worse--it would lock up while booting into safe mode, and I never got it to boot up.
I really hope that this problem can be fixed without too much expense.