Help! Ever feel like you've lost yourself in a relationship?

I feel like I was at my prime before we got together, he does too and now we've been together for over a year and we've both gotten lazier and gained a bunch of weight. It's odd, we were virgins when we met each other but I feel so disconnected sexually from myself, I was at my hoe stage when I met him (and super sexual, always masturbating, etc), nowhere near done, and he was supposed to be another guy but I just couldn't get him out of my head.

I was all about being attractive and done up and it's almost like I did that to find a partner and now that I have one it's like I stopped but I was single for so long it was just how I identified myself and it's been hard to balance everything

Our problem is how we see ourselves and our relationships with ourselves, we dove head first and now it's like we're lost but we're trying to find ourselves again.

Before we got together everything was so interesting, and now it's like we've both fallen into lazy, preditiable ruts.

Instead of being ourselves it's like we've molded into something else to suit each other or what we thought the other wanted and we've both stopped acting like the people we were when we fell in love.

Anyone else ever have this problem in a relationship?

We've both talked about how we miss ourselves back then, how we miss the single life but we both agree this is so much better and it's more of a "nostalgic" feel. I can't imagine not being with him and he feels the same way. I never thought I'd have this with anyone and it's honestly so beautiful.

I don't want to break up with him and I definitely don't believe I need to, so don't even suggest it.

Any help on how to do?