HOCD or gay

Hi everyone, did not know know where else to go or what to do, I feel like i am at the end of my rope so i figured i would explain what i am going through and see if you fine people could help.
First let me give you some back ground information, I am a 31 yearold male single virgin. I have been stuggling with homosexual thoughts running through my head since i have been about 12. I have always felt just very confused and worked up about my sexuality. while i feel deep down in my heart that i am straight and want to be with and marry a woman, i have always had these thoughts that i was gay. These thoughts are too the point that when i masterbate i think about muscle or fat guys, but its not in a sexual way, its them always growing bigger, i dont get any pleasure by this and i fill disgusting and gross and empty after, this also causes me to feel like my underwear is dirty and i feel the need to constantly buy new underwear to the point of throwing out all of them so i can have clean undirty one's (i have no problem with wearing underwear more then once or after its been washed, but its just always on my mind. i also find myself looking at youtube and looking at muscle guys or fat guys, i dont know why i do this but i feel compelled to do it, and its not like i get pleasure from it i feel gross and empty. It is so bad i even look at work, which could get me fired. plus i cant concentraight om my work because my mind is just constantly going your gay what are you going to do? when i am around other guys i feel like they think i am gay or when my mind is racing and i cant think of anything else i swear people know
i really want a girlfriend and to have sex with a women and they really do turn me on, but anytime i get anywhere close to asking one out i think what if we fall in love and get married and i really am gay that would tear us apart especially if we have kids. its just would not be fair, plus i am really shy so that does not help.and when i talk on the phone people confuse me for a woman
sometimes i just cant think of anything else but being gay and it just makes me want to scream, and it makes me feel like i am going to have a panic attack. this is ruling my life and i want to stop. i have high blood pressure from all of the worry and stress. i want to live and have control of my life
the stress also really make me itchy so i scatch and sratch untill i am raw.
i have seen i therapist for 3 visits, i did not help at all
sorry this was so long, what do you think hocd or gay, thanks for your help