It’s hard to comment on this, because every relationship is different, but if you have a bad feeling, my advice is to trust it. You can devote more time to changing your behavior, try to catch yourself before you tell him what to do and offer support instead. He’s dealing with a lot and it’s probably very hard for him. But if he’s not mature enough for you to feel comfortable with the relationship, then maybe now is just not the right time. That was a hard lesson learned for me, to realize that just because you love someone doesn’t mean the relationship will work out. Wanting him to be a different person is going to be very frustrating for you, because you can only help so much and people don’t change overnight. Not that he shouldn’t work on his flaws, because blaming other people and things for his problems is not going to help him. My ex had similar complaints about me, that I wasn’t mature enough and too dependent on him. Even though I’m still working through that loss, I learned a lot of things that I would have continued to be oblivious about if he hadn’t ended it. In fact, now that it’s over, I wish I had had the courage to end it first.

This is just my opinion based on my experience. He is hurting and maybe staying with him is a better choice for you both, a chance to support him while he improves and giving him support while he grows. But you should do whatever feels right to you. Good luck to you, you will figure it out.

This is tricky and I’ve been through it before myself (although i was the negative one).
One of the things that worked for me and my BF (we’re still together) was to each write a list of:
What we wanted out of the relationship (like, go on date nights, take trips, live overseas etc)
What I wanted to do more of as an individual (so things you may have been ignoring after a while… an old hobby, certain friends etc – we both wrote things we wanted to do individually and spend more time on).
Then, things we wish the other person would do (nothing totally changing – but noting some of the areas you would like to see a little change. For me I wanted my partner to be a bit more proactive in our social lives, as I was always the one planning trips and parties etc. and it was getting boring always been told yes to everything. There were some others but that’s one example) He wanted me to stop bringing up stuff from the past, basically learn to let go of old issues and in a sense, have the same laid-backneed as I did when we first met)
We then both signed the lists (corny I know, but it worked for us). Then we put the lists away (after a good read of each others and ours), and re-assess in 3 months time.
It gave us both things to work on and an actual timeline to measure it by. Because we wrote it down to begin with, it was clear and we both got our say, not an off-hand comment followed by interruptions and in inevitably miscommunication.
It might not be for you, but if nothing else, you’ll get an insight into what he’s thinking and if you’re priorities/goals line up.
Good luck!