So it sits there. Unpublished by anyone. I'll never know if nobody likes it until I hit the go button. But I'm also scared to learn that I suck at something I enjoy doing.
I went through a similar process to yours, with agents liking (but not taking) my novel. My wife has won literary awards for works agents wouldn't take because they couldn't see her stories becoming best sellers. Not just doing well (which they admitted they would do), but becoming best sellers! The entire publisher/agent thing is a bad joke on creative talent. These self appointed gatekeepers of our culture often miss the next big thing and are rarely looking for a new, different voice despite what they claim, but rather the next celebrity ghostwritten tripe where they can make a quick buck.
I can relate to your fear of rejection...I share it...but I'd encourage you to go for it. Make sure your book is professionally edited and proofread (this is absolutely critical, and far too many self-published authors don't do this). While you're doing that, figure out a promotional strategy. For example, line up bookstores in your area for signings, create a presence on goodreads, participate in book fairs, lit fests, and conventions applicable to your genre, etc.
Don't be too disappointed if you don't sell a ton of copies (it is very hard to get noticed), and don't measure yourself on that...measure yourself on how well people enjoy your work. That is the real metric on how well you write, and how good your work is. My novel Autonomy received all kinds of good reviews (from people I've never met!), but it's still not a "best seller." Just put your edited, polished work out there and if those who read it love it, then you don't "suck at something" you enjoy. Quite the opposite.