While it's appropriate and even helpful to have some perspective (you are in a good financial position, you hopefully are in good health, you are still very young), your disappointment and pain is still real. You need to process the disappointment.
After I took the time to just do nothing, here are some of the things that helped me get excited about something new. I think it's important to shake up your routine - you cannot just wallow in past thinking. You have to tell yourself to turn the past experiences into wisdom you have forever instead of constantly thinking of them as proof of failure.
Travel. New places are exciting. Maybe do something 100% guided so you don't have to do any planning. This can help bootstrap things.
Do new things. I find it feels good to be early on the learning curve of something new. Lots of feedback of progress, and it's fun. New sport, new programming language, etc. Even if it's entirely purposeless.
Do you have any lists of ideas you want to pursue from the past? Or maybe go read lists of ideas for startups that others have posted.
Volunteer at local startup events, or offer your expertise for free to other founders. You would be surprised how meaningful your experiences will be for others. You are in a great position to help them.
Hopefully some of these things get you excited about the future.
Good luck!