You aren't alone. My relationship is very similar but we are wlw. I still love her but I know I certainly need more in the relationship department because her chronic pain and mh means she ends up gaming all day when I stopped being as much of a gamer years ago. I will sometimes just ask her to do mundane tasks on my computer for me so I feel like we are doing something together. I have a really active social life but she has a couple of friends she socialises with every so often.
I've been thinking about it for a while so I thought adding my two cents from a similar position might help. I think being poly might be the right answer for me and taking over the room of another housemate when they leave.
I feel really fulfilled by my friends but I feel lonely in my relationship. I suppose that the difference is that it feels like some of will do cute little things to help me without being asked when my gf feels like she needs prompting to do anything more than look up from her screen and tell me she loves me.
I'm disabled myself and elements of my disability frustrate her too but she says that she is upset with the disability and not me and I feel the same towards her. I know that if she would pay enough attention to the real world that she would remember how much pain she is in, but I can't stop myself feeling lonely despite that.
I don't want to feel like I'm butting in on your post with this, I thought being upfront about it might make you feel a little less alone like your post did for me. :)