I have a 3 1/2 year old mare, she gets very nervous and stressed when she is around wagons and allot of horses. My vet suggested ACE can you give me any more advice, I have tried Quietex already and that does not work.
It sounds like your mare does not need drugs, but needs to get broke. I would haul her to shows, ropings, events, and tie her up to your trailer of strong fence for a few hours at a time and let her get used to being around excitement/events, etc. Drugs will only mask the issues and not fix them. Try getting her a little tired before she is exposed to things that bother her by longing her or riding her first. If she paws or gets nervous, just let her alone. She will eventually get over it. Good luck, and keep me posted.