Going back to work tomorrow breast feeding questions

I’m going back to work tomorrow only for the time being but I’m so scared of my milk supply slowing I don’t know how I’m going to be able to pump. I get zero breaks at work and I work with all men who can’t do my job for me to go pump. I may quit tomorrow lol I’m going to feed my son at 6 am then I won’t be able to pump until 8 ish and then who knows when again maybe not until 5 when I get off. How long of this would it take for my supply to dry up 😭