I think it's great you're confident and sexy. Also kudos to you doing 3 miles of swimming a week, that will definitely help your joints as you get older. Swimming is a great all round exercise so doing that regularly is a massive bonus.
But that doesn't make you healthy. Unfortunately weight alone, has a big influence on your likelihood of getting type 2 diabetes (if you don't have it already), high blood pressure and other issues. I'm 5'4" and can only imagine how hard it must be at times to move your body around for long periods of time. Bending down for things, crawling with your children (if they're young, I find I'm always on my knees playing, reaching for toys, nappies etc), walking up flights of stairs.
If you genuinely don't have breathing difficulties, joint pain or diabetes (or prediabetic) that's amazing, but I worry you may have it soon.
Being sexy has nothing to do with weight, we all find different bodies, faces, personalities attractive. I don't think anyone has mentioned plus sizes being less sexy (although realise the media do insinuate that smaller is sexier which isn't true).
My close family member was obese when I was growing up. They developed type to diabetes in their 40s, high blood pressure and have nearly died multiple times due to weight related influences on other illnesses. They're unstable on their feet miss out on a lot now due to a lifetime of ill effects of obesity.
Losing weight has nothing to do with increasing sexiness. It's about giving your body a chance to be balanced and reducing the pain and damage that obesity causes.