I think that we have established, from remarks made by people that know you, that there is nothing wrong with your vocal abilities. It's just getting the mind convinced that you can do it. :)

I started performing as a deliberate attempt to become a more extrovert person. I was a very quiet type and my first wife had died leaving me with a big gap in my life, but we had been regulars in the audience a sevaral folk clubs in our area. I knew that I had a better voice than some of the "residents" but I would never have considered getting up to sing. No problem with the chorus though.

So, I decided that I was in a vunerable condition as an introvert with my then current state of affairs and decided to change. I reasoned that if I could play an instrument as well then at least I could hide behind it to some extent, so bought my first concertina and after about four months was ready to let sombody hear me. I wanted to throw myself in at the deep end so to speak, so I picked a week when I could go to three folk clubs in succession. I set off for the first club. I could not sing and play at the same time but the usual thing was to do two or three numbers in a floor spot so the plan was to sing one and play one then either sing or play for the third item depending on the nerves. There was a stool up at the front that I could rest the concertina on and this was a great help. I leant against the stool to try and hide the fact that my knees were quaking. (I'd always thought that this was a literary invention but now I know it's real.) I was introduced and launched into the first song and after a short while it was easy! Composed myself further as I played my tune then on with another song.
At the other folk clubs in that week I once again started out nervous but found that I had nothing to worry about in fact, except that I would need to learn more songs for the next week!

I'm fairly sure that managing to repeat the experience several times in a short period helped in the long run so once you've got up and done it - do it again.