This isn’t about pills, it’s all in your head, clearly. I had exactly the same thing after my first marriage ended in a flurry of multiple women then found one really a bit too young for me and I had a few issues exactly as you describe.
So, some things to get straight in your head, it can and does happen to all of us, it’s just a matter of when and how, sometimes it can be drink, sometimes stress, whatever, it does.
The other ramification you must consider (this might make it worse for you) but she must be thinking it’s her fault, not attractive enough for you, something she’s doing wrong etc etc, so the problem is shared, only she hasn’t got anything structural to fix so to speak.
Edit Oh and try not to use any kind of drug ever if I can avoid it, so no to the blue pill.
Edit Oh and never use drugs of any kind if I can avoid them, so no I wouldn’t bother, fix the mind first.
I’d give it a rest, try and diffuse the situation then sooner or later it’ll just come back on its own, try not to think about it, use natures natural moments (piss proud in the morning) once you’ve done it once or twice it’ll go away, it’s all just nerves.
This is going to sound a boast, but since I’m in a totally anonymous environment I can speak about it, I never have until now, but my problem was exacerbated by personal physical issues in that I’m a bit bigger in the endowment area than I would like and have had ‘fit’ issues as well and it takes more to ‘get it up and keep it that way’ so I know exactly where you are.
All I can say is try not to let it get to you, make a joke about it, take the blame entirely on yourself don’t make her feel bad and get your ‘timing’ right, women are more susceptible at different time cycles and the ferramones work in both your interests, (bit like dogs and heat, we don’t like to talk that way, but it is true).
So good luck and my respect for bringing it up, I’ve been fine for twenty years now, but still worry every now and again and as soon as i do, I then have to worry even more, it’s a nightmare trying to forget so you can ‘get on with it’.
Edit Oh and try not to use any drug if I can avoid it so no to the blue pill