Adobe is screwing up my Mac

Two days ago, I kept getting pop-ups to let me know that the new Adobe Flash was in and that I needed to update. Usually, this is a one-time thing that I either install if I have time or just ignore and it goes away. I didn't have time at that moment to install, but however many times I kept dismissing the pop-up, another one would pop, sometimes two at the same time. Finally, I gave up and installed it. But it seems it came with other software that I didn't ask for. One of them was Meta Cloud -- I don't remember the exact names, but I started uninstalling them because they in turn kept popping up on my screen. Now, there is one called Advanced Mac Cleaner that I can't find in the applications and don't know how to uninstall. It keeps popping up and telling me that I have to clean my Mac and that it is conducting a scan of my Mac -- if I give in, it wants to charge me money. If I resist, it keeps popping up. I even got one pop up message telling that I visited a website that I may not want known that I visited and that I need to be careful what websites I visit. I thought that was particularly odd. I use this computer purely for business -- I never visit any website for any other purpose. Even if I did, that message would have been odd. I don't know if this is all coming from a hacker, but the Adobe Flash seems to have been legitimately updated. Now, I seem to have a problem -- my Mac just crashed. I have had this Mac for years, and that has NEVER happened. I think whatever was installed on it has affected its performance. I am really scared this is going to destroy my Mac.