I started in mid November and stopped in mid January, so about 2 months.
"Did you stop at the first sign of sexual side effects?"
I think I was in denial for awhile but I suddenly realised the harm it was doing and stopped when I had that epiphany.
"Did the sexual side effects ever get better or did they just seem to get progressively worse?"
They got worse and worse. At the start I had no side effects, in fact I think I had higher libido than usual. I didn't start suffering until maybe after 6 weeks or so, and even then it took a few more before I realised something was a miss and I stopped.