Zygopetalum, this is just a guess but did your computer problems start shortly after you downloaded some new software?

If so, you might have got a Potentially Unwanted Program (PUP). PUPs are bundled with software created by unethical people. PUPs are not malware but they can include spyware, adware and browser hijackers.

If you think that this applies to you then Malwarebytes can usually get rid of them.