We can all relate to the embarrassment of posting in a public forum - I absolutely hate admitting that I'm 370 pounds, but I am. The fact that you're doing something about it is the important part
. Trust me, if anyone understands it's this group and you're in good company.
I made the mistake of basing my previous bike purchases on standover height. I'm 6 feet tall, but I only have a 30 inch inseam. I also have large thighs. Being male, it's a different kind of "getting up in there", but it's still getting up in there, as it were. Much like the poster above, I very rarely use the standover position. So, I'd say pick the bike size on OVERALL comfort - if your upper body is more comfortable on a larger frame, and your pedal reach is good, the standover height isn't as important.
I finally just ordered a bike in the appropriate frame size yesterday - can't wait 'til it gets here
.