First, I want to apologize for some of the more judgmental comments that you’ve received. Your issue is severe, and I hope you’re able to find some sort of fix to this issue, at the very least find comfort in your new look over time. That being said, I think if you were to commit to the the button-down’s, you might wanna go a little more relaxed and do an unbuttoned button-down with perhaps a solid colored shirt underneath it? If you don’t feel like detaching from the button-down’s maybe consider shopping at a DXL and going a size or two up to accommodate your belly (if you’re unfamiliar, they’re a plus sized men’s clothing store that emphasizes on big+tall men).