I too think this is more about your insecurities than porn.
I'm also overweight, single, over 40 and have no problem meeting lovers. It's not about weight, its about confidence. I wasn't always overweight, I was tiny when younger and not nearly as confident and as a result had less sexual/romantic success. But initially when I started gaining weight my confidence reduced even more.
Something which started me thinking was something Kelly Brook said (and yes I know she's not overweight but she is considered larger in the fashion industry sense, plus note I said started me thinking), it was along the lines of noticing the difference between cover girls/models used by women's/fashion mags and those used by 'lads mags'. The ones on and in women's ones tend to be skinny even androgynous, but the ones in lads mags tend to have hips, boobs, bums, thighs and even rounded tummies.
Lose weight for health if necessary but don't think it makes you less sexy/attractive, if it did your bf would never have looked twice at you.
I've been complimented on stretch marks and cellulite ffs.
Even within my circle I have male friends who are very attracted to larger ladies and turned off by slim ones (not that there's anything wrong with being slim either) but everyone likes different things.
Porn can even confirm this, there's tons of very popular bbw, milf etc videos even whole sites devoted to them. If he's into lesbian stuff very little crosses over into curvier body types (which is ridiculous as lesbians come in all shapes and sizes too) probably just feeding into androgynous dyke stereotypes so that's what happens to come up when he looks.
Plus I bet he's no hunk himself! Men have insecurities too it's about how you handle them.