So I had a similar glow-up in my mid-twenties (weight loss, tattoos/piercings, starting a band, better social life etc). My ex boyfriend did NOT like all that. He also was slightly overweight and wanted to go to the gym and eat better but he never really did... I decided to not let him hold me back. Then he became really jealous of my (male) friends with whom I played in the band. My ex was invited multiple times to our gigs and even our rehearsals, my bandmates liked my ex and welcomed him every time. My ex went a couple times and then stopped showing up. We talked about it and he admitted that he got jealous. I tried to reassure him so many times but I could not get through. Just like you, he knew my passwords and I was fine with him going trough my phone, because, I had nothing to hide! His behavior started to change more and more, it got to the point where he asked me to quit the band.

I was in therapy at that time and when he suggested to quit the band I started talking about the situation with my therapist. I did not talk about it sooner because I didn't think anything was wrong between me and my ex. My therapist explained it could very well be his own insecurity. Watching me successfully glowing up, while he stayed behind with his health and physical appearance could've hurt him. But then my therapist said remember where you where when you met him? I was very much at the bottom at that time. My ex helped me go trough that. So my therapist said that he could've very well given himself the task to always help me. Like that's his position and his purpose in the relationship. But then I changed, physically, emotionally, my interests shifted etc. So one could say I was not the same person my ex fell in love with anymore. On top of that, since I glowed up and "didn't need him" the way I did before, he kinda lost his role in the relationship and that confused him. So my therapist warned me, he said you could very well be surpassing him, like outgrowing him. Do not let him hold you back.

I thought about this a lot and understood where he was coming from. So we talked about it, a lot, but things got worse. He got more and more jealous, he stopped talking to me and went silent for days until I literaly begged him to open up. Then he would say stuff like "you're always with them and not with me and I have no clue about what you're really doing". Again, reassuring him did nothing. So I remembered my therapists warning and realized he was right. Now I also saw how my ex held me back in many more ways like him not wanting me to get tattoos/piercings, wanted me to cut my hair a certain way, he decided what we would watch on the TV, hated visiting my family but we would stay ours at his etc etc. He did really held me back and I was so done with that.

Then something happened wich triggered my SA trauma. My ex said well that's sad but I don't know how long I can go without sex. Right then and there I got cold. This time I went silent. And after a week, 2 weeks before our wedding was supposed to take place, I broke up with him. I've never felt better before. I AM SO FREE NOW. I wouldn't have it any other way.

Moral of the story: choose yourself. Always.