I agree - regardless of the reason, they should not have treated you badly. Period and eclaation mark!

I would go to a new doc and let that new docs office request your old records (a professional courtesy extended gratis). I also suggest you compose a letter to your old MD's "boss" stating your reasons for leaving the practice. CC your old MD.

I bet you get a formal apology and also that they have a discussion of courtesy to patients at the next all staff meeting. This may not fix the problem for you, but you will hopefully have effected(affected?) institutional change.

Way to go for standing up for yourself as a human being and a patient. My hat is off to you