Read the comic here.
For those of you who are wondering about it, let me explain the version of time travel rules that I'm using for the Brick House. It's mostly the model that DC comics uses, with a few tweaks.
If you travel to the past you can't change anything. You can try, but you'll always fail for some reason.
If you DO manage to change the past, well, then you've created a new alternate timeline that splits off from that point. So you still don't really get to change anything. (Or you traveled back to an alternate universe to start with.)
You can co-exist with a past self with no ill effects due to the above. (Note that the characters aren't sure about that right now, so they'll continue to try and avoid touching themselves. As is good and proper for a mostly PG comic.)