how did you do this
Fight the warlock and lose to her. During her next option choose "make me a girl." As long as you don't have too low of stats (bottom i think?) you will become impotent.
If you befriend her the same can happen if you choose to be trained at the camp with her and choose the same option. Its one of my favorites but there is no going back. Not that you need to with alma there to take care of all of your needs.