Not suggesting you do or don't do it yourself, but you might read the book "Patent it yourself: your step-by-step guide to filing at the U.S. patent office" by

Not suggesting you do or don't do it yourself, but you might read the book "Patent it yourself: your step-by-step guide to filing at the U.S. patent office" by David Pressman from Nolo Press. That has a lot of experience in those pages. He has done four other books on the same topic that you might also read.