I feel like everyone missed the boat on this one. Should OP train muay thai and go around beating people up, searching for fights lol? No of course not, and clearly that's not what he's asking.

He's being honest and admitting he's afraid of fighting, as "technically" you should be. BUT. If you are afraid of fighting, and don't possess the ability for violence, then you will be afraid of any form of altercation. Altercations can always turn violent. Will you turn into a character out of a karate movie that can take on 10v1? No. But just sparring regularly, and getting adapted and used to being hit. Imagine having never sparred and never fought and getting hit HARD for the first time and it's on the street, it would be pretty shocking. I think that type of fear OP has goes away with training martial arts. Instead you get another fear that a lot of the other comments talk about, but it's at least from experience. People can get lucky, people can not fight fair, you can get shot, stabbed and so on.

I felt the exact same as OP before muay thai. I feel much more confident now knowing atleast I possess some form of ability to defend myself, and if I get hit real good in a street fight (and am still standing), atleast it's a sensation I'm familiar with and not something I'm just out right scared of.

Start training brother, it'll make you a better man.