Feeling disconnected from my boyfriend (24M) and not sure if it's the relationship or me? (23F) - need outside perspective

I (23F) started dating my current boyfriend a few months after a major life transition (graduating college and moving to a new city), about 5 months after ending a 4-year relationship. I've been feeling disconnected for a while now. I don't get butterflies, sometimes I struggle feeling attracted to him, and finding myself wishing I'd had more time alone before getting in another relationship.

The main friction points: he has an anxious attachment style/struggles with abandonment issues, and needs a lot of reassurance that I feel like I'm already giving. We have really different communication styles I'm more private and process things internally, and he wants to know every thought I have. It works for him, but I feel like I've had to give up a lot of my autonomy to keep him comfortable. He's also gone through my phone once (and went searching for conversations/text messages about my ex) which I tried to move past but it's stuck with me.

On top of that, I feel like I've lost myself a bit. I had a really structured fitness routine and personal goals that I was deeply invested in, and since the relationship (plus a demanding job, 50+ hours a week) entered the picture, I've completely fallen off. My personal time is almost always going to other people, and I don't have the energy or willpower to reclaim it even when I do get a moment alone.

He hasn't done anything majorly wrong, and there are genuinely good things about the relationship. But I can't shake the feeling that this has been building for a while. I don't know if I'm just burnt out and need to communicate better, or if something deeper is off. How do you know the difference? How can I even be a good partner going through this?