Timeline Issue: Please help

I did something and I don't know why my timeline changed to this. Seriously, there's got to be a way to revert this...

Also when I play from the beginning, it gave out a compiler error. So the playback is screwed as well. I need this resolved as soon as possible because I have a deadline going on... Thanks

Update: I'll just stick with the previous file that I saved two days ago. So whoever responds is still relevant. I'll like to learn how the problem happened and how I can avoid it next time if it can't be fixed. 🙂 Enjoy new years eve!