Paper or doctorate thesis?
A thesis is only one part of a doctoral program.  Generally, there are also classes, qualifying examinations (to make sure you have sufficient breadth and depth), and general apprenticeship as a researcher.  The goal of all of this is to prepare you for a scientific career (whether in traditional academia or elsewhere), which requires more than just the ability to produce a single project once.  In my experience and observation, life as a practicing researcher typically involves producing another Ph.D. worth of work every year or two---a Ph.D. thesis is just the capstone demonstration that you have been educated enough to be capable of doing it at least once.

As such, I think that it is unlikely that any good institution will allow you to skip straight ahead to using a completed project as a thesis, no matter how good the material.  If you want to use the work as an entry-point into academia, I would instead recommend publishing it as a paper paper and simultaneously using the work as a springboard for admission into a good Ph.D. program.  If your field supports use of preprint archives, this is a good way to put your paper formally out there even while it is going through peer review.

If this is truly the direction you want to go, don't worry about rushing to the end-point.  As other questions on this site indicate, age need not be a bar to an academic career.  Instead, I would recommend that you take the time of graduate school as an opportunity---if your independent experiences give you a head start, so much the better for being able to do even more awesome work during graduate school, and also better positioning yourself for what comes after.