@FeelingUnworthy gosh I am so sorry to hear this.
I'm sure it won't help much but fwiw my dp has health problems that limit his energy, travel, etc. He has to sleep more than me and at different times, he has dietary requirements, sudden bodily needs that he can't plan for and that can make outings stressful for him, etc.
I had no idea of any of this when we started dating and it was only over time that I realized what was going on.
It is absolutely mortifying for him, he is a independent, stoic person who hates asking for help. And he also has experienced enormous loneliness over it. Everything you say, I can hear echoes of what he has said to me about his experience as a chronically ill person. Again. I know that doesn't help directly. But maybe it helps to know that invisible illness tends to affect folk in predictable ways - this isn't a "you" problem, it's part of being ill and how our society reacts to illness.
In terms of me and DP. We are happy together. I am an extremely healthy person in general, but I have needs of my own as well, which he accommodates, it's part of how we express love to each other. Our lives have a slightly different texture compared to other people's - we have more naps, more quiet weekends at home, we plan downtime into trips, we take note of toilet facilities and places to rest, and so on - but you know what, it doesn't matter, it's just life.
I don't think you should throw yourself out with the bathwater (so to speak) just yet. EVERYONE has special needs. We all do, some are just seen as "illness related" and some are "preference", "culture", etc. etc., and everything in between. There really are all sorts of lids for all sorts of pots.
It will be OK, but you need to feel you've got someone on your side for now because you sound depressed and discouraged, and that can become a vicious circle when it comes to chronic health conditions. Loneliness and sadness make folk sicker, make symptoms feel worse, and make more vulnerable to infection and all sorts. And it causes you to self isolate which will make you more lonely.
I think counselling would really help. Can I suggest "empowerment-based" counselling, sometimes called "feminist" counselling (but it's not just about feminism) - someone who has experience with disability would be amazing for you.
You aren't alone. You sound lovely. It will be OK in the end, but you do need to take action to get yourself there.