My ex was shy, had SA, was NOT a movie star looking guy, was awkward and in 47 years had never even had a REAL kiss by a woman. He had never held hands intimately or hugged in a relationship way. Yet I fell so completely head over heels in love with him that it still aches when I think of never being a part of his life.
His thoughts about himself and his life and his perceptions eventually destroyed us as he would push me away further and further until he finally just broke up with me because 'being in a relationship was too hard for him' and 'he couldn't get used to the affection I wanted to share with him.'
We were together for a year... 6 months of absolute heaven before he started to give up and stop trying or fighting for us and stopped communicating with me. We have been broken up now for a year and we still email, I still love him from the depth of my soul and with all of my heart... but I can't force him to be ok, I can't fix him and if he can't be with me and would rather be alone then I have to step back and let that be where he is.
But don't generalize and tell me that awkward, shy guys with SA are doomed to be alone because a woman will never find them attractive. More likely they will sabotage themselves out of fear and self-loathing and give up on the one who will love them.