Waiting for my boyfriend to grow up... I don't know how long I can hold out.

Hey r/relationships, I've been feeling really down and out lately about this situation, wondering if anyone can offer some advice.

I'm F (21) and he's M (22). We've been together for about 1 year now and we both just graduated from college. He's going to graduate school about 3 hours away next fall. For the summer, we've been living together, and some things have slowly started to become more clear. These things have made me lose a lot of attraction to him, both physically and emotionally.

1. He is very sensitive. Often, when I try to help him with his diet (he has blood sugar issues) he gets very defensive, even though his improper eating makes him incredibly crabby and unmanageable. When he eats poorly, he sleeps all day, misses class, performs poorly at school and becomes sad and upset. I would love to speak nothing of it, but his inability to regulate his diet ends up hurting me later on. I often feel responsible for his emotions, that anything I say could possibly offend him. Furthermore, food is not the only issue. Almost anything that could be perceived as criticism is taken poorly. I often wake up at 3 AM to find him playing video games when he has work in the morning. I know he is going to be so unpleasant the next day, but when I tell him to come to bed, he gets very defensive.

2. When we get into debates, I don't feel like he intellectually stimulates me. I know that sounds horribly pompous and I feel terrible for even thinking it, but it frustrates me to no end when I try to explain some concept to him or discuss some subject with him, and I feel like I need to walk him through the most elementary concepts with him, almost as if I were teaching a middle schooler. He is incredibly smart at what he does (physics), but when I try to talk to him about politics, philosophy, or economics (which is more of my forte), I struggle with talking to him. At first I thought because I cannot converse with him about his field of interest, I thought it was only fair to let it slide. But as time goes on, I feel more and more frustrated with having daily conversation with him.

3. I don't feel like he understands money. I'm fairly certain he has had all his amenities and comforts provided for him his whole life. He has never held a regular job with enough money to pay for rent, cell phone, insurance, etc. While I am not completely financially independent either, it makes me uncomfortable that he seems to have such little concept of it. He eats out almost daily, never seems to hold back because something is too expensive. He also becomes sensitive if I question him about that.

The worst part about all this is that I really do love him. He is a wonderful, gentle man who adores me. We make each other laugh, and we have similar ideologies and attitudes towards people and life. But lately, I've been feeling like that love is becoming the sort of love I would feel for a child. Someone I want to take care of, and someone who's hurt is also my hurt. I cannot stand the fact that I feel like I am falling out of love with him. It's killing me. I wonder if maybe once he starts grad school, he will start to mature, start to learn to be a little more financially independent? I don't know.

For a while, I thought he was the one, that I could see him as the father of my kids, as the man to stand by me for the rest of my life. I'm beginning to doubt myself. But breaking up with him would devastate both him and I. I don't know how he would handle it, and I certainly don't want to make his transition to graduate school any harder than it needs to be. I love him dearly, and I feel that if this relationship must end, I would wait until he was a good way into school...

Even then, I have NO idea what I would tell him. That I've fallen out of love with him? I can't do that to a man who has literally NO idea that these thoughts are running through my head. And I am reluctant to say that it's a matter of long distance, because he has suggested he would transfer schools for me. Reddit, I love him so, so much. Please, some advice? Thank you all for reading, you are wonderful people.

TLDR: I think my boyfriend might have some growing up to do. What should I do?