I've seen that trend @Captain24 - I've had that trend in my life too.
It is definitely good to raise it with your MH nurse/team next time.
For me, I used to have this build up of anxiety leading up to a social event > then I'd attend and finish on a 'high' > then I need the next day or two to 'recover'
Period after the event used to include a lot of 'post-mortems' if you get what I mean. That is, 'I should've said this', 'I should've done that', 'I shouldn't have said...'.
It was also a type of emotional dyregulation. Being so anxious, then heightened, then the body trying to maintain equilibrium so emotions crash.... can you sort of see a trend/graph. Have a look at this:
This is social cognition of BPD versus 'neutral'.

OMG!! I can't explain this better myself! Have a look at these graphs below:

Norm is the blue line. I'm the red line....
This is the first time I've seen data on what I experience in social settings!
For Example, at a social situation, most neutral people's emotional state is quite low, but for a BPDer like me, I am so emotionally heightened (anxious). During the event, I continue to climb, and even after the event, I am still emotionally heightened - much more than 'neutral people'
Sorry if i'm not making sense... I'm just excited to see this data.