Put a fork in it, it is done. It’s hard to finally accept the ending of an endeavour you have committed to for years. Especially when so many others are telling you to keep fighting, that it takes a long time. But you need to understand what to stop fighting against, and how to change your approach.
If you were trying to escape from a bulding, you wouldn’t only keep trying a single door. I would hope you are going to look for other ways.
Take from your failure lessons. Reflect a little bit. Look for a different door and get after it again.