Wow, there are sooooo many things I relate to in your post.
First--being too high functioning to have DID. Sometimes, even today, that thought still crosses my mind. I think it's just another form of denial and identity dissociation for me. It's so much easier and less complicated to just think I'm quirky, or forgetful, or that I'm making up all this stuff like stories in my head, because if my DID isn't real, and my parts aren't real, then I don't have to face anything about myself or my past. I was thinking I'm too high functioning to have DID right when it was becoming the most obvious--one part was talking to me and taking over and talking to a friend of mine. That friend, thankfully, is still my friend, and tells me anytime I feel like maybe my parts are not real she will gladly remind me they are absolutely real and will let me read her journal entries to prove it. I'm glad I have her to remind me, or I might go around and around in my forgetful circles. Then I wonder how I could have gotten through nearly 4 decades of life without anyone knowing... But then, there have been people in my life who met parts, or witnessed a breakdown. And I also have forgotten people who were friends. And I too have wondered why I can't just be normal, and do more, and handle little stresses that others do just fine with. Funny that I didn't wonder why I had long conversations with myself in different voices for as long as I can remember. Funny that I swore I didn't have any parts but when I talked about my past I described times when I would be a different person, with different motives and mannerisms and ways of dressing. I said I didn't lose time but there are large pieces of my memory that are just absent, and often someone will mention having a conversation with me that I don't remember at all. I've held jobs all these years though. Never been fired. I think DID has been the reason I've held jobs and look normal to most people. When I experienced work stress I dissociated those feelings. Overworking kept me from ever having time to think about things or feel things. When the stress led to a breakdown I was sick for a few days but somehow could hide the worst of it. All but one of my friendships is superficial and one sided. I'm good at keeping people at a distance. I spend a great deal of my personal time alone.
I haven't dared tell any family because they were all super at denying things growing up (everything is perfectly fine/nothing happened/stop feeling sorry for yourself) and I am sure that they will say nothing that bad ever happened to me. After all, if it was that bad, they would have to face that, and they can't.
Actually though, and this may sound strange, I don't know--I like my parts. Therapy has helped me connect with them and I have gone from scared to glad. They help. They have always helped. If some things they did were not good decisions that was the best we could do at the time, but life is far far better now that we know each other. I never could have coped, and quite frankly, survived this long without them. I have a strange little family in my head, and I wouldn't have it any other way. It took some time for me to come around to feeling this way. Letting go and allowing myself to take in the truth of my partitioned condition went against the powerful denial that had been _our_ way of life for always. It was hard, and scary, and several parts did not want that denial to stop. But now here we are, working together.
I hope you find that encouragement you are needing.