I sympathize greatly with what you're saying. Though I think for me some of the things I've noticed are positives, as strange as that might sound (although it's hard to say how much of a change in perspective is due to age vs illness). However, I've only been completely bed ridden for two years now, so things might change if that continued longer term. I'm lucky enough to be slowly improving on the whole for the last while, which makes things much, much easier to take. The journey down was much harder.
1) I have WAY fewer inhibitions than I used to. I remember a time at my lowest where my husband was literally dangling me from his arms trying to get me into a wheelchair at the hospital while a bunch of other people stared and stared and stared at me. It was awful, and I was totally humiliated. But I've gotten much more accepting of difficult situations like that than I used to be. I think once you're having strangers shower you, you're pretty much a pro at that.
I suspect that if I ever recover enough to be back in the world, I will be much more authentically myself and be more willing to put myself out there.
2) I have a very solid understanding of what is really important and what really isn't. There I things that I dearly want to get back in my life, like seeing friends, and going out to dinner with my husband, and doing creative things, and having new experiences, and traveling, and learning new skills. I'm quite sure that if I ever do regain my energy, I won't be spending it working overtime anymore or doing things just to please other people or meet their expectations. I've got a much more solid grasp on my priorities now, and the importance of actually living a life that's in line with them.
3) I've been one of the extremely lucky ones who had a spouse before I hit bottom, and whose relationship has gotten stronger through this journey. I think any major crisis that hits a couple will either break people down or cement them even closer together. This one took a major toll early on, but the longer we deal with it, the stronger we've become, and we're closer now than we were before I became so severe. I recognize how very, very fortunate I am in that.
On the down sides...
4) I am missing out on a whole phase of life. Not only will I likely never have children of my own, but I'm also missing out on meeting my friends' children, and seeing them grow, or being involved in their lives in some way while they're young. And because of this, I'm also not growing with my friends who are going through that. They'll be in a whole other place by the time I can see them regularly again.
5) Some of the friends I though were closest have vanished. And that is really, really hard. And the others have grown progressively more distant since I'm almost never able to spend time with them and even then the most I can do is have a quick chat. I wonder sometimes if my personality is shifting because I spend so much time alone and only see the same one or two people these days (husband and care worker).
6) I sometimes feel like I'm losing control over my life, home, etc., which upsets me greatly. Slowly the people taking care of me are developing their own systems for doing things, their own places to put my stuff, their opinions on how to take care of it, etc. and my house is evolving into something I wouldn't recognize. I'm not even sure how to explain why this hits me so hard, but it does.
7) I feel constantly frustrated like I should be able to single-handedly come up with some brilliant idea for how to raise funds or awareness for this illness. I am desperate to make a difference somehow.
8) I may never fully trust doctors without doing my own research again, even for things unrelated to this. ...Though on the plus side, I will always now have a better understanding of my own health and take a more active and informed role in it. And I'm way, way better at listening to the cues my body is giving me and taking them seriously. I shudder at the symptoms I brushed off or tried to downplay to myself before I became so severe. They were important. I was a moron.
9) I'm a bit more nervous around people now, I think. But the people I knew before getting really ill just don't interact with me the same way anymore (they're stiff, or nervous, or awkward much of the time, and many friends just don't interact with me at all anymore), and people who didn't know me barely register me now. When I'm out in the wheelchair, they talk to my husband who's pushing it but their eyes slide right over me. It's difficult to still feel like an accepted member of society, and I think that's gradually having a negative impact on how confident I feel about social situations.
