When I was in my 20’s, there were absolutely no bbw’s in my circle. Not even someone a bit overweight. I fell a few times in love with a slim girl because I liked their personality. Luckily it never worked out. And I say luckily because this falling in love was purely platonic. There was absolutely no sexual attraction. I was in love with them, but I would never have been able to have sex with them, or if I had, it would have been very unsatisfactory, fantasising about bigger girls. Once I realised that, I have gone exclusively for big girls.
I hope it is different for you, but take some time to think about it. A true relationship is not just about sex, but it should also not just be platonic. Sex is an important aspect of it, so make sure that that sexual chemistry is also present.