I have only had sex with guys but don't consider myself gay. I am attracted to women, but I can't just have sex with any woman. When I was 11 I had my first experience with a girl, but it was my younger half-sister, so, of course, I was hard and able to have sex, and to me it felt really good, but my parents caught me. I was 11, so not really knowing, but instead of them teaching me, they beat me half to death. After that I just stuck with guys. I made an attempt to have sex with a woman for the first time when I got married, but it went terribly wrong. Her breath was terrible, her body was not attractive to me and there was hair down there, so it just was a terrible combination for me. I hate that I ever had to go through this in life. I am dating a girl now and she knows all of this about me and is really attracted to me and admires me being strong, despite all that I have been through. But I fear not being able to have sex or make love with her when that time comes. I can get hard when watching heterosexual porn. I just don't want to run into the issue of not being able to please a woman, especially my future wife.
Your note certainly contains a different twist though the root problem remains the same. Homosexuality is not what you find attractive or sexually appeal. Homosexuality is the act of having sex with someone of the same gender. "For this reason God gave them up to vile passions. For even their women exchanged the natural use for what is against nature. Likewise also the men, leaving the natural use of the woman, burned in their lust for one another, men with men committing what is shameful, and receiving in themselves the penalty of their error which was due" (Romans 1:26-27). While you don't consider yourself a homosexual, you have been committing the sin of homosexuality.
It sounds as if you missed a lot of education when it comes to sex. Most eleven year olds would not consider having sex, let alone with a younger sister. May I ask how such ideas got into your head?
Another problem appears to be pornography. I would like you to read Lies Pornography Tells Men. What pornography depicts is not real life. It sets up expectations that cannot be met.
You mentioned being married before. May I ask why that marriage ended? Marriages are generally supposed to last the lifetime of the couple (Romans 7:2-3). Marriages that end in divorce generally do not allow the individuals to marry again, except to each other (I Corinthians 7:10-11). The one exception to this is if a marriage ends because of sexual sins by the partner (fornication), only in this case is remarriage allowed to the partner who was not sinning sexually (Matthew 19:9).
As you noted physically you are able to have sex with a woman. That is true for every guy because that is how the male body was designed. The problems you had with your wife are not physical but mental. Your mental attitude toward sex is trainable. The problem is that you have been training your mind wrong. You have been allowing yourself sex without restraint; in essence acting more like an animal than a human being. It is past time to grow up and learn to act as a Christian. "Therefore, since Christ suffered for us in the flesh, arm yourselves also with the same mind, for he who has suffered in the flesh has ceased from sin, that he no longer should live the rest of his time in the flesh for the lusts of men, but for the will of God. For we have spent enough of our past lifetime in doing the will of the Gentiles -- when we walked in lewdness, lusts, drunkenness, revelries, drinking parties, and abominable idolatries" (I Peter 4:1-3).