Good morning @destructive
My suggestion would be that you look for a counsellor that is specifically trained to deal with the effects of trauma - your gp should be able to help with that (just say that, they shouldn't push so you don't have to stress too much about explaining your symptoms or anything) and you don't have to tell your family that's what it's for, you can just say it's to have someone to talk to, same as anyone else.
Having someone who's already working with trauma backgrounds is gonna be important, and as an added bonus they will also just naturally have come across dissassociation because it's a linked condition.
It would take the pressure off of deciding what possible diagnosis you have, you can just talk to them and things should hopefully become clearer...
I would personally go that route, rather than going straight to a psychologist or psychiatrist because the sad fact is that it's not a condition that all of them recognise or are equipped to deal with (no excuse, I definetly think they should be) - I can understanding wanting a diagnosis to have an answer but you can get insight from "just" talking about what's going on with you with a counsellor - remember, YOU'RE the one who has the answer, not someone else.
(Sadly, I've got an adhd specialist psychiatrist who I mentioned childhood trauma too (not did, just something that I was anxious about at the time) and she legitimatelly just brushed it off and tried to put me on a bunch of anti-psychotics...it shouldn't be your responsibility but w both trauma and dissassociation, not all psych professionals are created equal)
If you wanted to get diagnosed later, I'm weighing that up also (we're saying dissasociative condition w my mental health nurse, but she can't diagnose and I'm happy to leave it at that) but besides that sense of knowing, like I said, there isn't actually any medication specifically for did or one set treatment.
If you want to chat, pls reach out : ) I get about the mood swings, I actually got very tentatively diagnosed w bipolar aaaaages ago and it never fit, now it's obvious like my mental health nurse said I don't actually switch moods, I switch states so that might be true for you too - I would assume most people with childhood trauma and/or disassociation go through a fair bit of wrong diagnoses because it's quite a complicated thing