Stijloor, you typed what I was thinking when I got to your post!
First, greetings from a fellow Texan, and welcome to the Cove! We're sure glad to have you here.
I'm pretty sure you know this.. but.. remember the process map is for you.
Too, IMHO, a good process map is not a five minute process. So many well-intentioned people are busy with doing their job and don't necessarily spend hours thinking about the process. It may take some time to get out of everyone what the product actually goes through.
I greatly encourage you to post your process map here. I've been amazed at the level of expertise of many Covers here. Too, please don't forget to ask the people involved with the process.
I might do a fish diagram approach on this (obviously fish diagram is not a process map, but is a good way to visualize starting the process map). Start with the majors, as the others suggested. Get the main process movements of the product. That should minimize your anxiety a bit. Well, you've captured the obvious; now capture the minimals.
Take your process map to the shipping person. Ask them if everything is on there; red-line it. Then, take it to the next person on the floor and ask them if everything is on there, and so on.
If you find yourself beating your head against the wall, then maybe you should remind yourself there are others who can help you.
They know the process; let them give you the correct information.