weird repeat happening in sections of timeline

[eawood_]

Hello, I have just started using AE for my grad school class, and am currently editing a "lyric video". I was trying to make the video appear full screen for playback, so I hit " control ~ " keys like I do in Premiere. This did nothing and I continued hitting them a few times as I sometimes do in Premiere when it does not work initially. I eventually just tried to watch the video back as it was, but certain portions now skip back to the beginning or go back a few lines, and it will not play the the next section until I click to the spot manually. I tried going back to an older saved version, but couldn't seem to locate one that was new enough (ie w/ my most recent edits).

I am a total AE beginner, so in very simple terms, what could I have done? How do I check what effects may be on my lyrics/in my timeline, and how do I nix them?

THANK YOU FOR ANY ADVICE!

[Mylenium]

Preview without rendering in After Effects

Mylenium