I find gitlab a great deal harder to work with than github I am afraid. While you can sync the remote from the web view on github, on git lab you need to fetch from the official lazarus and push that up to your own remote gitlab repo. Its very messy IMHO.
Sorry, I don't have my notes available right now so cannot be explicate. The broad idea is that you must try and keep your remote close to the Lazarus one. These changes you made to testall should be contained all in the one directory ? If so, I'd consider tucking them away some where safe locally and cleaning out your repo, and, maybe even your remote one !
I know its not the git way of thinking but your changes will be self contained, easily grafted back into a fresh repo when you have tidied up.
Davo