A Cold Burning sensation? overdoing it maybe?

*Putting this here for now will delete from the other thread if responses are better suited here in this one*

Ahh guys just had another session (my best ever yet again!), had to stop again early but not for the usual reasons, its a little more interesting a reason, any help or anyone had this?

- put aneros in, within a minute of 10% contractions, having lots of pleasure
- 40-60% contractions later amazing fun and great feelings
- one felt like i was about to orgasm, just like my last 3 consecutive sessions
- throughout the session i felt a warmth in the prostate which later turned to 'cold' when doing nothing
- the warmth then turned into... well, 'burning' not painful but not exactly comfortable
- the burning then changed into the most intense warmth in there felt amazing
- at one point the heat was at the very tip of my semi flaccid penis as well, not for long though
- then the burning returned, i wasn't contracting hard but it was there enough to force me to stop

The burning isnt 'painful' per se as i said but it isn't far off, at times the burning was 'nice' ?? which imo makes no sense.

I have felt this burning before when i used to use hand wash to finger myself in my ass, when i couldn't get to any lube, tried this a while back and it was like when you use mouthwash, that kind of cold burning sensation in your mouth after you spit it out, but in my ass instead. I was very subtle in my session and not overdoing contractions etc.

I narrowed it down to a few things that i could be (to help eliminate it) but would love to know if I'm right in thinking this:

1. The lube i use is irritating me after a time (its water based though and hasn't caused an issue before) i could try olive oil/shea butter etc?
2. when i pulled out the device had a little bit poop (!) on it, not abnormal but not a common thing wonder if this caused it somehow.
3. When i wash my device i use a shower milk (basically a moisturising shower gel though its closer to moisturiser, it contains flower extracts one being 'black orchid') possible irritant?
4. I've been having sessions every day for 3 days i think now, maybe 4 and its overstimulated (didn't feel a burning sensation in those sessions previous to this one, but i did feel once before some week ago). Though my progress increases by leaps every day from doing this, don't mind giving a rest but my sessions are quite short, like 1-2 hrs tops.
5. its normal for some people and is just part of the rewiring process and its not actually a thing to be concerned about.
6. i'm wrong in my perception of it and its not actually uncomfortable at all

'Burning' isn't quite right as a term as its not the same, its cold somehow as well but at times it IS hot as well, and at one point it was 'warm' in a way that was just... well... f*king awesome! my feeling is its related to stimulation as it was be less intense a feeling when i relaxed totally... so i think it could likely be either number 1, 2 or 4, would be good to know before i start another session perhaps tomorrow or the day after.

So is this normal or at least heard of? i don't want to push things or do damage somewhere.... my sessions though lately are just getting better... and better and BETTER! I don't want to stop if I can...