For me, lots of things I used to struggle with suddenly made sense and now I have strategies for coping with them that actually work. Whereas previously I would try various strategies and end up hating myself when they didn't work.
I used to drink far too much - that was a way for me to quiet the noise in my head - and now I'm aware (and have meds), I can drink sensibly.
I used to be late for everything - this is because I hate waiting and would rather have been late than have to kill ten minutes doing nothing. Now I know, I give myself things to do before the meeting (or whatever) starts.
I used to have a long-running internal conflict between my need to plan and control everything and my desire to "go with the flow" and take things as they come. Now I understand there are some things that I need to keep tight control over and all the rest I can just let it happen.
It's possible I would have come across these strategies without the diagnosis, but I'm in my late 40s and was only diagnosed last year. I had been failing with all the strategies I had tried and it was resulting in me hating myself and feeling inadequate that I was unable to cope with things everyone else seemed to find easy. But now I know the cause, I know where my boundaries are and what I can and can't "fix".
(As for blood pressure - mine was borderline high but it actually fell once I started taking the meds - I assume this is because I was actually more relaxed and able to cope with life).