"Will this keep me from passing either a 1st or 3rd class medical exam?"

Probably not but let a specialist give you legal advice before you go to an AME. If your doctor is not familiar with the process and fills out wrong forms, etc. you might be facing lengthy delays in getting your medical. www.leftseat.com is one place I would research (not cheap, probably $400-$1,000 for them filing out the forms for you). Maybe others can recommend some other sites?