Well, this is a tough one, but mostly because I fear I have to point you in a direction that might shock you. Your equipment works perfectly well when you are on your own which tells me that you do not have a physiological problem. The issues pop up when we add a woman to the mix. You chose your girlfriend because you like her and you find her attractive so I am baffled.
Are you afraid of something?
Might you, perhaps be afraid to defile her with your sexual urges? In our sex education, many of us are taught that 'good girls don’t'. It’s the bad girls who have premarital sex and the bad girls who want sex; meanwhile, good girls wait for marriage and even then they only have sex to please their husbands, not because they want it.
This thought pattern termed 'the madonna/whore complex' has damaged many a marriage bed when men find that they cannot screw their wives, rather they have to 'make love' to them in a well-mannered way that does not offend.
Good manners and extreme politeness does not make a sex life great, so these men save their 'real desire' for whores and loose women.
If this sounds like what is going on in your mind, I suggest you seek help from a counsellor who can help you work through this issue. It’s not uncommon and you may find that you resolve it relatively quickly.
If you aren’t turned on by women, at all, then you may be a homosexual. It is time to ask yourself some hard questions and you will find that a counsellor dedicated to listening can also help you come to your own conclusions at your own pace. I wish you all the best in this journey of self-inquiry and remember that there is nothing wrong with you if you do indeed turn out to be gay.
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