Is it Priapism or not?

I'm finally having some success with my injections, but it's a little strange. If I do 10 units (30-1-10, I think ), it's not enough, but at 12, I'm hard for 4+ hours.

But it's different as the hours go by. The first hour is rock hard. The second the shaft is really hard, but it'll bend down. The third hour, I can walk around in pants and push things down and it's fine. Same at hour 4, but the shaft is still hard. It is not painful in any way. And I can get rock hard again, if I want. But it usually take until hour 5 before things start to get flaccid. Is that bad? I used the antidote a few times at 4 hours, just in case. But I sort of feel that if it's not painful and it hangs low (though semi hard), maybe it'll just settle down on its own.