My situation is not dissimilar-- 28 years old and halfway through a second bachelor's in nursing, which now seems not optimal. I'm currently applying to PA schools.

MD programs are also an option I've considered, and though I'm a little older than you I already have all my prereqs done because my first degree was in biochemistry, so we'd probably be about the same age when we finished up. I'm mainly hesitant because, as you say, it takes for fucking ever, and I suspect I'm going to want to have babies less than ten years from now.

PM me if you want to talk more; we could bounce ideas off each other.

ETA: Consider giving yourself the opportunity to fail cheaply: see how you do with your science prereqs, take the MCAT, shadow a psychiatrist to see if you actually want to do that, etc.