random STTN and engorgement - ouch!

OK i know there is no magic answer, but yikes, how do you deal with the boob pain when your LO is only sporadically STTN?  the past couple of weeks my DD was slowly starting to sleep a lot better, we would get a 5-7 hour stretch each night.  my boobs were slowly adjusting and would hurt a little but i wasn't pumping because i wanted to get used to that schedule.  but then she regressed it seemed, and the last couple of nights she was up every 3-4 hours.  (maybe the four month wakeful, slightly early for us?)  for night wakings, i always just change her if necessary and then feed her and she goes right back down.

anyway tonight she has been asleep for over 8 hours now and of course i am WIDE awake, not just to check on her but because i am uncomfortable.  my right boob overproduces anyway, and man it was like a ROCK, so i just pumped a few ounces to relieve the pressure.  but i didn't empty it, and i didn't pump the underproducing side cuz it doesn't feel as bad.  i keep expecting her to wake and need to eat any minute but i have no idea.  am i screwing up my supply by doing this?

how do you deal with it as they randomly STTN?  

and maybe this means when she does wake in 3-4 hrs at night, i should be trying to soothe her back to sleep instead of feeding her. but it's so hard to know what she wants and i'm tired so i just nurse...