I'm 82 And Use Cialis. The Day After A Prolonged

I'm 82 and use Cialis. The day after a prolonged encounter with my lady friend, my penis felt as though I'd had an erection for too long and my penis seemed swollen. It's been a week now, and the pain has diminished a great deal, but when I get an erection the pain seems to return but not as bad as the few days after the prolonged encounter. What's happening and how long before the pain goes away completely upon erection? Thank you.