First I'd check (if you have insurance and it's simple) with a medical doctor and see if something's up there.
How long have been jerking off and how frequently? If you power through a few days without it I'm sure your girlfriend will have no problem getting you up.
At my peak I'd be jerking it 6 times a day, now it's about down to once or twice a day.
I guess cold turkey is the only option
Yeah 6 is definitely enough to introduce your dick to some dysfunction.
Try to go as long as you possibly can with out it then no more than one from now one. Even better just fuck you're gf when you need to. Use a cock ring