Problems with

I just recently got into creating online-experiments, because I’m working on my Bachelor dissertation and due to Covid I won’t be able to run it any other way.
So I created my experiment and followed all the steps in the guidlines for online-experiments.
As it seems somewhere was a bug and now everytime I try to sync the experiment, the following error message appears:

Traceback (most recent call last):
File “C:\Program Files\PsychoPy3\lib\site-packages\psychopy\app\builder\”, line 1227, in onPavloviaSync
retVal = pavlovia_ui.syncProject(parent=self, project=self.project)
File “C:\Program Files\PsychoPy3\lib\site-packages\psychopy\app\pavlovia_ui\”, line 533, in syncProject
File “C:\Program Files\PsychoPy3\lib\site-packages\psychopy\app\pavlovia_ui\”, line 119, in showCommitDialog
File “C:\Program Files\PsychoPy3\lib\site-packages\psychopy\projects\”, line 962, in commit
self.repo.git.commit(’-m’, message)
File “C:\Program Files\PsychoPy3\lib\site-packages\git\”, line 548, in
return lambda *args, **kwargs: self._call_process(name, *args, **kwargs)
File “C:\Program Files\PsychoPy3\lib\site-packages\git\”, line 1014, in _call_process
return self.execute(call, **exec_kwargs)
File “C:\Program Files\PsychoPy3\lib\site-packages\git\”, line 825, in execute
raise GitCommandError(command, status, stderr_value, stdout_value)
git.exc.GitCommandError: Cmd(‘C:\Program Files\PsychoPy3\MinGit\cmd\git.exe’) failed due to: exit code(128)
cmdline: C:\Program Files\PsychoPy3\MinGit\cmd\git.exe commit -m _
stderr: 'fatal: Unable to create ‘C:/Users/BenSc/Dropbox/Studium/Bachelorarbeit/.git/index.lock’: File exists.

Another git process seems to be running in this repository, e.g.
an editor opened by ‘git commit’. Please make sure all processes
are terminated then try again. If it still fails, a git process
may have crashed in this repository earlier:
remove the file manually to continue.’

So I googled it and as a result wanted to delete the online-project to reupload the new version.
But my problem is now: Since I uploaded it, some time passed (and I had a lot of exams), so I forgot my password and no matter what I try, I won’t get that password recovery-mail.
So I created a second account. But the problem is here, that I can’t figure out, how to connect the old project with the new account, because as it seems it always tries to sync it into the old account even when I log into the new one in PsychoPy. If I close PsychoPy and reopen the project I’m also already logged in into the old account.

It would be very nice, if someone could either help me to get into my old pavlovia-account or tell me how to sync a project with a new account, which has already been synced with an old one.