Hmm, your experiences sound nasty and discouraging.
Between lots of reading, asking the old-timers and free training seminars our vet puts on for our county youngsters, we have learned about general doctoring/maintenance. We can’t afford to have the vet do the things we can do so we do it ourselves.
I am not a guy. My husband has nothing to do with the horses so we girls have figured out a lot of this stuff on our own, by watching, reading and asking. Also, being part of a the 4H community has been an invaluable experience.
Really, that is all it takes for one to effectively and efficiently care for a horse. The clinic I have can trace its veterinary heritage back to 1911 and there is a good lineage of knowledge of what works, what is practical, and what is obsolete.