Losing weight will only really help your self esteem (probably your health in general which can be appealing to others as well). You're putting yourself out there which is important, try not to make everything you do a search for a potential romance though lol.
25 is very young to think you'll never meet someone. Doctors and Lawyers can take a while to get to finish school so you're not exactly alone. If you're awkward at 25 it's not a big deal tbh, don't sweat being the only single guy in your friend group. I'm sure there's a few guys you know in committed relationships who may wish to trade places with you