URGENT: I have no idea what's happening; I think I gave my computer a virus?

[980]

It may have been from downloading some game off a website or maybe from browsing tumblr but I positive I gave my computer a virus. I'm using Google chrome as a web browser. Pictures on tumblr do not load like they did before and gifs are always freezing up and not loading. Videos do not come up on Youtube or websites that I use to watch anime. A green screen comes up and I cant hear any sound or watch anything. I already disabled hardware acceleration. I scanned my computer with avast! and it found two infected files, so I did the recommended action that it had selected. However, it seems that didn't do much as the issue still persists. I'm freaking out and am tempted to wipe everything on my computer. PLEASE. Does anyone have any sort of idea of what I should do?