Aless

You can have a sore prostate or soreness in the pelvic floor, sphincters... I think the contractions could continue during the night, we would have to ask the guys that sleep with the Aneros. Personally when Aless contraction wake me up, they're only at the beginning stage and just getting started, I don't wake up already "pumping away" like mad, so I don't know about that. If you're getting worried about this, see a professional. Sometimes it's the only way to put the mind at ease, you'll have lots of trouble making progress if you think you might be hurting yourself or worsening something...

Not that I want to dissuade you from seeking medical advice if you need it...when in doubt ask a professional. 

I've read here before people who have written that "their body tells them when it wants to have an Aneros session."  And when I get aroused and my prostate is telling me that it wants the Aneros one of the sensations I will have is what I would describe as an "ache" in my prostate.  In fact one of the things that's been happening in the last couple months is that my prostate will feel small and hard; other times it throbs rhythmically, sometimes gives me a prickly sensation.  All these are different feelings of prostate arousal that I've experienced.  I wonder if what you are describing and I am describing might be some of the same kind of Aneros horniness...