While building a business is a commitment, it doesn't have to be permanent! Throughout my experience as an entrepreneur I've built numerous businesses. But, after a certain time I've moved to do something new and exciting. I urge you to be patient. You will likely have the opportunity to bring another idea to life, but each business is more likely to succeed if you are able to put your energy into developing one idea :)

Freelancing is likely to be a great option for you.

I run Expert360, an online marketplace for freelance professionals. We focus on bringing businesses and freelancers together to get work done, often within days or even hours. The site gives you the freedom to bid for contract work that interests you and suits your professional skills. Kind of like a matchmaking service, but less romantic. Freelancing will give you the flexibility to work on growing your business, while also developing your professional skills and giving you a stable income, no matter where you’re based.

Ironically, I used it in the start to supplement my own income whilst I was trying to build a business. :)

Freelancing is a great option, as it will allow you to utilise the skills you are likely to have
gained by creating a startup, while also giving you the opportunity to work on a contact-to-contract basis and it can be immediate (for $1000 anyway).

I run an online freelance marketplace for experienced professionals called Expert360.com. Our online workplaces empower businesses and freelancers to come together regardless of where they happen to be, to get work done. If you create a consultant profile, you can view projects and apply for relevant pieces of work. A number of the companies in need are start-ups - so perfect :)
Good luck!