4 Days later. Advice please

Hi all,

I stumbled across this forum while researching prostate massage toys. I Would of been content with a bit of kinky play with my wife and at best I more intense TO for myself during sex... Probably something that vibrated and would end up at the back of a draw in a week or so.

Staring to read through forum posts it quickly became apparent that this was a big deal and I became fascinated. 48 hours later i have the helix syn. With a few days of alone time ahead I followed the wiki and started the journey. First couple of days very little happened as expected. Just tried to relax and feel any sensations down there coupled with very light contractions and breath work. On day 3 the helix began to jump Round while I held I very light contraction. Yesterday scared the crap out of me!! The same invoulentries started but with every breath the grip got tighter. Till all off a sudden my whole body began to shake uncontrollably. Hips thrusting and arm flapping around.... this point I'm glad I'm alone.
These convulsions felt like a full body workout more than anything pleasurable. I tried to straighten my legs at one point and my back started to spasm and arch backwards, this was very painful causing me to stand up and shake it off.
Managed to recreate this muscle shaking another 3 times but had to stop due to muscle fatigue although I was trying to relax as much as possible. Also had an expanding feeling in my chest that increased and held with every breath like something was building... This just died away when my body became too tense. At the end of all this I was left with a very slight tingle of pleasure down there that lasted about 5 minutes.

I feel extremely lucky I am getting such response to the aneros so early on.
Any advice you have on what might be happening here and how I should continue would be great.
Is it normal to experience these extreme physical reactions with no real pleasure so early on?

Thanks