What is the machinist about?

DEFINITE SPOILER ALERT!!

it's about a man who has insomnia and is sickeningly skinny he has a haunted past or "suppressed memories" that bring out things about him he never knew he also meets a man named Ivan (who doesn't exist) a waitress named maria and her son Nicholas (also not real) as the story unravels his prostitute girlfriend and him have a blow out because he thinks she is part of a conspiracy that had made all of his friends disappear all these people are really just people he created in his mind to cope with the fact that he actually hit and killed a small boy (Nicholas) and his mother ran into the street (Marie) Ivan was just really his murderer self (many odd happenings occur because of Ivan men lose limbs and he goes on a car chase to find out who Ivan is and get his license information they wont give it to him so he jumps in front of a car to get the information and finds out it is his own car that was called in totaled a year before!