Stop The Research!
At some point you have to say no more.
You’ve got what you’ve got. You need to write it up in your thesis in a way that makes sense for your examiners and others.
You have to believe that it’s enough.
You have to stop at some point but make sure that when you do you leave things in a good place. Make notes in case there’s anything you have to come back to or you want to return to at some point.
At some point you have to stop the research. Make sure you stop well.