I can't help you with how to feel about your weight issue, but I can tell you that when I meet people on the ship, or on excursions, my first impression as to whether I'd like to get to know them better is not how fat or skinny they are. It's all in the way they act, if they are having fun, laughing, making friends, those are the people I want to hang with!! You could be a frickin movie star, but if you are sitting with folded arms and a sour puss look on your mug, I'm not coming near you!
If you are happy and having fun THAT is attractive to others and people will want to be around you.
Nobody cares about how you look in your weight but you, and if they do, they are caring about the wrong thing. Well loved ones care about your health, but I mean if a stranger doesn't give you a chance because you are fat, to hell with them.
Don't give up on the experiences you want to have (snorkeling and jet skiing) because of the weight, or the weight wins. That's the saddest thing to me when I see a friend (I'm 46) who isn't too old to do something, but she says, 'I can't, I'm too fat.' To me that's giving up on yourself and the experiences you could be having. In the words of Nike 'JUST DO IT'!!
"Life has no limitations, except the ones you make."