I was a bit concerned when I read the end of the OP about achieving the body you want. Are you wanting to do it for yourself, or in the hope that he will find you attractive enough to date you?
Took me decades to learn this, no one told me, but I figured it out from experience and from observing others: In general, when someone is self-confident no matter what their body looks like, it's that confidence and self-acceptance which shine and draw people to be attracted to them. That's what's sexy, not the body type. I look back at all the years I hated myself because of my body, and when I lost weight and felt more attractive, then I got more folks attracted to me. Now I'm somewhere in between, feel good about myself regardless, and still get the same amount of attention. In fact, I do things like dressing down and wearing a fake wedding ring to draw less attention because I'm not interested in being approached. It's the self-attitude that is the draw, not a particular body style. People want to be with people who feel good about themselves, and if you feel good about who you are regardless of your body type, then there's no pressure to maintain it and no loss of self-worth if it changes.
A case in point from an observation: I had a neighbor who I was not at all attracted to. Suddenly, after a few years, I found him attractive, and I was confused by that. Then I realized what had happened. He'd gotten in a relationship and was really happy. He had a new sparkle in his eyes, he carried himself differently. He didn't have the greatest body, and his body hadn't changed. I found him more attractive because he felt more attractive, confident, and happy. But if all that relied on outer rather than inner acceptance, then if he broke up with the woman and didn't feel good about himself as a result, I would have found him less attractive again. I didn't see how it played out, I moved when the relationship was still new.
