But do doctors just write a prescription for it even though you don’t have a problem with getting a boner? Should I find a shady online doctor who will?
Well how old are you? If you are over 50, you just say you have difficulty getting boner. That's all that is necessary since ED starts at ages 50-60. For younger ages you say, you have difficulty unless girl friend sucks your dick (which is standard provider procedure). Say, when she gets it up, by the time you put condem on and try to stick it in, it wilts.
The main problem is if you are too young like 30, he's going to do a work up to understand whether it's phsiological vs mental. You can say that it's always been difficult with anxiety, like first time in bed with a girl. You hadn't complained about it previously since you were embarrassed and it wasn't that bad, but it's gotten worse recently. You think it's mental, since you can masturbate OK, but it goes down quickly.
Boners are easiest when teenager, guys will just get them sitting in class, but as you age, they become progressively more difficult.
It's a quality of life issue which is medically now more important. It's not about not getting sick, but whether you can have good sex.
So, what is your erection difficulty?