I feel I am in the same boat! I have a long-term gf we have been together around 6 years now!
She gets really agitated when we won't have sex for a long time. We sometimes go a good 3 months without doing it, and she is a very beautiful lady and I do feel attracted to her physically. Although she constantly makes me feel guilty for masturbating when we are not together, especially because she noticed some nude pics on my mobile (not the trans kind though).
Then of course I have had the same problem with other beautiful women too, sex with them doesn't seem quite right, I don't know how to explain except that masturbation seems to feel better is some respects. Either I have been with the wrong women, or maybe it's something psychological.
There was a time I was afraid, I would only be able to get it up to jack off to a trans ladyboy, but I soon found out that isn't true! I'm attracted to women, but I haven't managed to understand what is wrong yet.
It's not like I need viagra, because I can get really hard powerful erections when I'm excited. It's just that if something awkward happens during sex, like she says something ridiculous I immediately lose my erection and it won't come back so soon.
This never happens when I'm jacking off to internet porn! Once I did it for 4 hours straight online, but if I last even more than 30 mins with her she will complain that the reason I last so long to cum inside her is because I don't find her attractive anymore... or that I don't like her, which isn't true
, because I love her to bits!
Also I made the mistake of getting one of those FL to help me masturbate, now instead of orgasming in 3 minutes it takes me ages to do it, almost 35 minutes or so, sometimes more... I thought this would be a good thing, only apparently it isn't, because now when we have sex I can't orgasm in time with her.
Maybe I'm really messed up now...
True honest story...