Firstly, this is amazing, I love that your denial has taken you to this place, it’s rare and wonderful.
The best news though, is you probably can’t cum, not like that. If you truly avoid any physical stimulation then you’ll just feel as though you’re on the edge and be completely unable to go over.
But you have to be very careful, if you get to that point the slightest thing can do it, a brushed nipple, pressure between your legs, even standing up too fast.
I’ve know a couple of women who’d get like this, and then cum from being throat fucked! Even that was enough to take them over.
If you do cum from it though, it’s often half way between an orgasm and a ruin, but again it can vary. There’s no stimulation to take you over, but similarly, nothing stops to ruin it.