After having skimmed through what you wrote, some friendly advice, condensed:
There are plenty of fish in the sea. There's more than you have time for, actually.
Focus on quantity. Enjoy every single one of them. Collect experiences. Based on what you wrote, there's definitely room for exploration in your life.
You'll not only bounce back, but you'll grow as a person. You'll most likely kick yourself while muttering "what was I thinking?"
If you're having trouble dealing with all this and/or you're busy feeling sorry for yourself, consider the following:
How much time do you have left on this planet if all goes well and life doesn't throw you a curveball, like an illness? Can you afford to waste even a portion of that time crying over this? Should you?
If you're still having trouble processing it, consider whether any of this will matter in 5 years. It won't. So don't waste your time and enjoy your life. You have the privilege to choose freely. Take advantage of that privilege.
ps. Regarding your professional life -- Scale down your lifestyle (if you're broke don't try to live in London). Get a job, be scrappy, resourceful and hustle to build your business on the side.