I am sorry to hear about your situation, but I don’t understand why you are letting it affect you. Not giving a toss about what people think isn’t the easiest thing to learn, but once you have it, it changes everything.
I have dealt with bullying in school days and in the Navy, so I know the pain only too well, mental and (unfortunately) physical, but I haven’t met a lorry driver yet who would worry me, and i’ve met some right sorts. I’m confident that I could wrap a tyre iron round the cannister of even the fattest meat heads, should it come to that, but that isn’t the point is it? Unless you read Robert Heinlein, does violence ever really solve anything?
It’s a solitary job at the best of times, most bullies are covering up for an insecurity, so it is their problem, not yours. Don’t let yourself be a convenient offload for their issues. In the world of a lot of these guys, lorry driving is all they have to act superior over anybody, they are probably fat, have a small ■■■■■ and have a domineering and ugly wife who hates them, and kids who won’t pay them any mind once the opportunity to fly the nest arises. They spend their weekends knocking back the special brew, and waiting until they can get back to their cab to act superior all over again.
Don’t let people walk all over you, and it rarely if ever needs to come to violence. Though i’ll grant you in the simple world of most ‘wagon drivers’ violence is sometimes they only thing they understand, don’t lower yourself.
If it comes to violence then you have failed, to make an impact on somebody this way, you have to take them down hard, none of this “would you care to step outside thing, queensbury rules” its a quick blow with something hard that they (or you) won’t be getting up from, and a hospital menu in their hand. Probably an assault charge for you, and a no more job.
Have some confidence in who you are, what you do, and how you live your life. To hell with them.
The true alpha male in a given pack is rarely the one who feels he has to prove it all the time.