My Anti social younger brother doesn’t reciprocate.

Should I stop caring about being a good big brother and wanting to be important/involved/relevant in my younger brothers life who I’ve helped so much over the years, he has shown me very little appreciation and reciprocation etc. at some point I feel absolutely taken for granted. He only contacts me when he wants or needs something. Yes, once or twice he has “been there for me”. But as a rule I have been there for him through everything. Rehab, medications, stress, almost suicide attempt (because of med changes), etc and at the end of the day, I truly feel he could give two shits about me. I offered to rent to him for a good deal, he lives in my next door apt. That shouldn’t be relevant. But he seems to have almost zero interest in being my “friend”. I’m his older brother. I’ve always initiated most of our interactions. I just feel taken for granted. He probably is just used to it. He probably doesn’t know “how” to be a good loyal younger brother.

My philosophy and logic recently is: I need to respect and accept that he is anti social. He also just got married. I wanna give him space. On one hand I would “like” to feel that he might want or need me for advice but I also wonder if after he is settled he will come around. But I am realistic enough to realize he may never be who I hope he could be. But I am not hopeless about that. I am rooting for him cuz that’s what I fucking do…

Anyone understand? It’s just frustrating. I literally feel like his dad sometimes