Hi!
I was also diagnosed not long ago and started connecting the dots and I am slowly minimising the denial.
I don't even find it a bad diagnosis per se. I was borderline. I still am, I suppose, DID is related to borderline/extension of it in some cases (some say).
Anyhow yes, it feels like making it up. Even if it makes sense, it feels... so strange. I am scared and started being all escapist and watching United States of Tara day after day instead of working and such.
But I do not feel like I am switching. Until I face some of the consequences. Knowing I have alters and not ADD or being bi-polar, it makes a lot easier to deal with life.
For example I feel like I am losing it, I sit down for a moment and think, hey, wait, who took over. It's you, MyMother and Headache, well no, I do not need you now. And I talk them out from being the ones 'in the front'. I was in the store about to make a ridiculous purchase and realised it's the small one. I hid in a aisle and talked to her and explained that we will get the fun things later, but not now. I didn't even mention money, she knew, I think I was much nicer to her than the previous 'main' alters and I went out of the store sound, without cold sweat and a huge amount of money translated into toys.
I have a very scared one, too, and when her emotions take over I talk to her or try to get the very calm Boy out to make her stop fear shadows.
So this diagnosis was very/is very beneficial so far. If it is what it is, it's better to know what we are dealing with- because then we can find the right ways and support.
The 'me' now, the main one (I still have problems with nomenclature, big time) that is, ME as in the personality that was somehow elected to wake up and take over, responds to different medications than the others. For the first time the meds help without making me feel worse- so far. And I could quit mood stabilisers, which was impossible before.
I am writing so much about myself

Just want to somehow get the point across, DID diagnosis is really not terrible. There are so many ways to cope that are not accessible with other diseases. You can always have help from one of your alters if all else fails.
Hope to hear more from you. Best, be well and yeah... hugs.