If your motivation levels are pretty low, you may want to delay job searching for a bit. Looking for the right job is hard and comes with its own setbacks that you need to be prepared for.
I started looking for a job in May. It takes a lot of time finding the right kind of company, going through all the interviews, and determining whether there's a fit. It's very draining and, of course, rejection always stinks.
You probably have a lot of great skills you picked up from building your startup, but practically no interview judges you on that kind of experience. I've encountered two main assessments: the take-home challenge and algorithm coding. Honestly, algorithm coding punched me right in the face when I started looking for jobs. It took me a little while to get back into the algorithm mentality (leetcode helped a lot).
Take home challenges are frustrating. You can put in a whole days worth of effort with no guarantee of getting to the next step where you can talk about your awesome startup experience. What's worse is that you probably are interested in the company because, otherwise, you wouldn't have put in the effort in the first place.
If you aren't ready to face this yet, I recommend picking up small coding jobs for a bit to get your spirits up and work on interview prep.