Try submitting to Thought Catalog. The ARE a few other publishers that accept that length (the "middle" zone between magazine article and a book), but they're mostly geared toward fiction or serialized works. TC actually takes more nonfic than fiction and accept one-offs.
I think self-publishing is your best bet. Now, whether or not self-publishing is worth it is a highly personal decision. It depends on what your goals are, not only for this piece but for your future writing endeavors.
If your goal is to make a ton of $$$ and become famous...then you should likely wait for your next project because that's not likely to happen. Depending on the quality of your book, your platform and your marketing, you might make a little money, or none at all. The odds are not in your favor.
My goal when I self-published my parenting book (which is only 48 pages) was to learn a few things about self-publishing, and make my mistakes on this one before I publish my next book. I also hoped to garner some good reviews to to help build my "reputation" as a writer. Money was not one of my goals.
So by own definition of success (based on my goals), my book has been a huge success. I've learned a lot about self-publishing and marketing. Some things I'll do the same next time, some things I'll change. The reviews have been a blast. I do a happy dance with each one! I love that I have an audience (however small) for a project that otherwise would have been trunked and never read. Money-wise I haven't made back what I put into editing and the cover. It's only been two months so that may change, but I'm not worried about it. As I said, money was not my goal.
Because I was clear in my goals and realistic in my expectations from the beginning, this has been a great experience. I would definitely do it again. Your milage may vary.