It's nice that the business can stay afloat with its current revenue, as that gives you some stability while you are looking for another job. So, it seems like a good time to be interviewing for other positions. There's no guarantee things will stay that way - with no clear roadmap, more changes may be coming that might limit the company's ability to stay afloat.
I don't necessarily see the lack of VC funding as a red flag. Is VC funding necessary for this company to succeed? Are you only interested in staying if there is the type of massive scaling that a VC generally requires? Or are you happy working for more of a bootstrapped lifestyle company?
That aside, the picture you're painting is of a job that you are staying at because of some level of guilt. Please don't let that keep you somewhere you are unhappy. Life's too short for that. They will find someone or they won't. People leave jobs all the time. It's totally normal. A business that cannot survive that is a business that is not going to survive anyway.