If you can afford it, do it. It will help you when you need to get accommodations at work.
And if you were in a special education class, you had a diagnosis. It's likely your diagnostician was arranged by the school (they tend to work for social services, and they have access to schools because a lot of needs for their services are first identified when kids go to school and interact with others for the first time), and a diagnosis was a part of getting you into special education.
I'll openly admit that the last time I did it, it was mostly to update diagnoses (I was late-diagnosed, but that was still in the 20th Century) and ensure that my therapist actually knew all my diagnoses. Because she didn't. Hell, my shrink never ran the full workup because they were able to get the info relevant to treatment from my GP.
I don't want all of Reddit to come flooding in all at once.
But one thing I've noticed is that the entire Fediverse has a lot of instance-specific stuff going on. It's really a question of finding the right instance for you. For example, I didn't particularly like mastodon.social as an instance of Mastodon, but I've found other instances where I gel with the userbase well. It's actually made the experience more pleasant.
If you're willing and able, setting up a Lemmy instance for some specific community is actually a good idea. During my holiday break, I'm going to be working on setting up Lemmy for my town and maybe even a club website that I have been assigned control over. .world will suffice in the interim.