Internet shuts down and then ads are popping up?

[Mary]

I was in the middle of watching a video on YouTube, suddenly Chrome closes on me. I try to open it up until my PC protection program notified me of a threat. I clicked the 'Clean Computer' option and I got the all clear. Now I pick up where I left off. Suddenly ads are popping up, but I have an ad blocker. Also there is a bing search bar on the YouTube page and there is no way I can't get it off. However, it did sign my out of everything. Facebook, my email, etc.My protection program is currently scanning, but I don't understand what's going on if I have all this protection. Nothing is expired, I don't want to deal with all these ads and slowness again. I really hope that I don't have a virus. That would completely suck and I don't want to spend money on getting my computer fixed.