You've received excellent advice above.

I'll just add that you are not alone. Many parents learn more about themselves and their gifted issues as they grapple with helping their gifted children. Remember that your parents did not have the internet and the ready support which parents of gifted children can immerse themselves in today. Your parents were most likely alone, without the BTDT advice of other parents, or the readily available research and articles by experts that we have access to now. They would not necessarily have known that many gifted and high potential kids may have challenges created by lack of academic challenge, lack of intellectual peers, and/or learning difference or disability... including executive function issues. The website Understood.org may be of interest.

Live and learn.

At 25 you can most likely complete college. You would need to devise a strategy. For example:
Strategy 1: shortest path to graduation. This option minimizes both time and expense. Analyze your credits and options available, including part-time attendance and online options. Look at transfer credits, CLEP tests, credit for work experience. Removing the constraints of any particular major and/or institution, how soon could you graduate, what institution would that be from, what degree would you have?
Strategy 2: path to degree from a preferred institution and/or preferred major. This could be your strategy for a higher level degree such as a masters or PhD. Recapping your experience and lessons learned from implementing Strategy 1 could be a compelling admissions essay... or potentially an article which you sell/publish... or even a presentation such as a TED talk.

What would you find to be the most doable? Most healing?

If you are in a slump look at local job postings, read the Occupational Outlook Handbook (OOH) online, read library books and online articles in your areas of interest, be a life-long learner, keep a list of books and resources you've delved into, and generally reinvent yourself.