I haven't rolled too often and most of my comedowns haven't been too bad, but there are a couple that stand out to me.
One time, I went to an outdoor rave in the middle of the NJ pine barrens and had a roll (orange star, we found out later that these pills were probably piperazines by this time, though they used to be good :'[ ). During the whole time, I didn't feel the true MDMA euphoria, and I actually felt pretty self-conscious around all those people I didn't know. I drove back home (about an hour or so) after the rave and the comedown didn't seem too bad, but after I went to sleep and woke up the next morning, I felt like total shit. All my muscles kept tensing up and I couldn't stop shaking. I drove to get food and liquor (my boyfriend wanted some), but during the drive I started feeling a whole lot worse. My hands were curling up and I couldn't hold them properly, and I felt so lightheaded and dizzy. When I parked at the liquor store, I wasn't even thinking correctly anymore and I couldn't see straight. I felt that I was going to faint or something if I didn't put my head down, so I laid down in the parking lot next to my car to cool down. Some man came up to us and asked if I was okay... must've looked weird in a liquor store parking lot, some girl laying on the pavement and some guy trying to "help her"-- or is he REALLY trying to help? Haha.. After I got some food, I stopped shaking so much, but still felt shitty the whole day and just slept it off.
Another comedown, we got in trouble with a cop for attempting to go camping on an "illegal camping ground" and I had to deal with the cop when I was starting to come down, then had to drive all the way home from the mountains after wards, ugh.