my boyfriend is so dependant on everyone in his life

My boyfriend (21M) is dependant on everybody to remind him things.
He was coddled growing up due to health conditions, i wont go into detail but I believe this plays a huge part in the way he is now.
We have been together for almost 4 years now and I have tried everything I can possibly think of to help him. The problem is, he also doesnt seem like he wants to help himself. He seems content with everybody doing everything for him, and reminding him things. Since he grew up having everything done for him, he still thinks he can live like that.

For example, he is on different medications for his health condition, and recently has gone days without one of them because he ‘kept forgetting’ to get it from the chemist. His mother had to keep reminding him, and so did i. Another example, he stopped going to his usual barber due to bad service, and has since not bothered to find another. Its been over a month, his hair texture is super frizzy and he doesnt do anything to keep it tidy, so it looks quite bad at the moment. When he is reminded to do something, he will usually say “i’ll do that in a sec/later” and then forgets. So I sometimes just wait and see if he will remember, but he never does. And then i remind him again, he says the same thing, and this continues another 2 or 3 times.

I have tried to step back and see if he will figure things out and do them, but nope. He wont. And all these things he needs to do build up and even if they’re really important, he suffers the consequense of forgetting, gets a lecture from his parents or older brother (yes, its that bad), rides it out and then just…doesnt change. He just takes it as it is. He also just goes with the flow a lot of the time, he wont plan the future out. Like if something important is coming up, he wont prepare for it or he will forget to do something in advance.

It’s impossible to not acknowledge this situation. I have tried to help him, as a partner would, i do not want to parent him at all, this is why i am reaching out. It’s so difficult to handle, as im younger yet more mature and independant but i dont want to break up with him. I’ve brought this up several times, and everytime he just says he will change and it’s at a point now where he’s even saying “i know i’ve said it so much and you dont believe me now so i guess i’ll just have to prove myself, but i promise i WILL work on myself” and then literally the next day he’ll go back to normal. I have spoken to him about his mental state, he has been in places before where he felt depressed and honestly i could see it in him. Right now, he has a great job, and a great life, and I can see he is happy. I honestly dont think he is suffering mentally, and that this is a problem rooting back to his childhood and being coddled and unable to get out of that, but i cant estimate the reason for his lack of willingness to change, my only guess is that he is scared to become independant. I just want to know whether someone else out there relates, or if you did, how did you overcome it, and did it ever stop? I cant see us lasting if it continues but I love him so much and we have so much together, i cant imagine that being the outcome.

TL;DR
My boyfriend was coddled his entire life and is now dependant on everyone around him, and it’s impacting our relationship.