If you want to keep your current business going while you study, then you probably want to study near that business, and study part time. If you have a partner or partners who can take care of the day-to-day stuff, then you could consider studying in a different part of the country, or studying full time, but with a load light enough to have the time you will occasionally need to deal with business issues.
If you were in the Boston area, I’d suggest Harvard Extension. Yes, it is a bachelor’s degree, yes the professors are often regular Harvard professors, yes you could take some regular undergrad classes at Harvard, and yes you would have access to the Harvard libraries and facilities. Depending on the course of study you chose, and your work experience, you would be able to put together a profile that would make you a good candidate for a solid graduate program if you wanted one some day. https://www.extension.harvard.edu/
Given your business experience, if that is the direction you want to go, some MBA programs (especially Executive MBA programs) admit some applicants who do not have a full undergrad degree. The MIT Executive MBA website has this to day: “We will consider candidates without undergraduate degrees or with fewer than the recommended years of experience if they have demonstrated exceptional capabilities through other endeavors.” Google a bit to find others.