Rainbow, I really feel for you.
Try not to feel alone in this, because many of us here experience many of the same things you do. Also, I have talked to several people who don't have fibro and they are also feeling awkward and anxious about talking to people, are forgetting things, losing things, feeling fog, or experiencing a lot of stress. I think many people all over the world are experiencing variations of this because right now we are in a sort of- maybe---well, carefully....can we?....sort of transition between lockdown and what will eventually be a new normal way of life. This is very pervasive. I have read articles about it, and so on.
My point being that the world wide circumstances are affecting hundreds of thousands of people in this way. And for those of us who have fibro, it is probably worse because we already have those issues at the best of times!
I have found a couple of things that help. One is, of course, to work harder than ever to keep my stress level down as much as I can. another is to try to find things I can treat myself to (like....I actually went to a movie! I was the only one in the whole theater, and it was great.)
Another thing I just realized recently: If I try to act normal around people (the normal we used to have) I just get more tense. So instead, I decided one time to embrace my awkwardness and really embody it and put it right out there.
So, I was in a group of people who all know each other, but together for the first time in over a year, and I just addressed the group and said, "You know, I am feeling incredibly awkward here. I feel as if I have completely forgotten how to talk to people, and no longer know how to behave properly in a group!" And it turned out every single other person there felt the same way, and that eased a lot of the tension. Not all, but a lot. I don't even try to act "normal" any more.
I also don't look at myself in the mirror unless I really have to.
I have to check my list of things I need to do every day. Sometimes three times a day.
I write myself a note if I have to do something in the morning so when I get up I don't forget.
Etc.
I have asked others, who don't have fibro, and some of them are doing the same things, when they never had to before.
Sorry for such a long post. But one more thing: a tip about the phone and keys. Especially with the keys, decide on a place (I like a hook in the wall just inside the door) and always, always, put them there as soon as you walk in the door. That way you cannot possibly lose them. As for the phone, I only keep mine in one of three places, all of them in the living room, even if I have to go out of my way to make sure I put it in one of those places. No exceptions. If you have a very small place, make it just one place. That way you never lose the phone.
Take heart. You probably are not going into dementia, just experiencing the same discombobulation every one else is feeling, exacerbated by fibro. It may very well get better.