I get it OP. I don't think its any coincidence that you got married to someone from outside the UK. I don't think the British really do romance and to me, having grown up outside the UK, a lot of relationships seem very superficial and easily replaced.
So basically I was a young successful woman with a job, financial freedom, AND a perfectly normal appearance without anyone fancying her. Why?
In my limited experience, a lot of guys here prefer plain women who are a bit needy because they think they can control them/don't have to put a huge effort in. My friend was recently dumped and one of the reasons given was that she "wasn't plain enough" (for him). I had an obviously disabled friend at work who was a magnet for all the creeps, she literally used to go out at lunchtime to get a sandwich and come back with some awful guy's phone number, having given him hers, and he would phone her up to try and arrange sex. A lot of guys want to exploit what they see as vulnerability (thankfully she never went) or alternatively, easy availability.
Looking back, the ones you have to chase after aren't worth pursuing. I had this guy, lets call him B, at uni, who you have thought I was ideally suited to. We did the same hobby, we both went on to work in graduate jobs at the same uni, but he kept messing me around really badly. He told me he wanted to go out with a "tall busty woman". I won't go into detail about what he did but basically when we moved away, he suddenly stared pursuing me for sex, I turned him down as he wasn't offering a relationship and he then turned up at our hobby with a girlfriend who he had had all along who was definatley neither tall or busty!
I also think that a lot of guys do prefer very slim women. You say you are a medium, but some men, who have this idealised view of women in their mind, would prefer a size 8. I know its not realistic!
Look on the bright side! At least you don't have hordes of creeps chasing after you, sending you dumb pms on social media, thinking theyre in with a chance with you, which is actually quite insulting when they are really rank!