I was "fired " by my primary Dr. as his patient. Can Drs, do this without just cause? Could the Dr, , undr certain circumstances, be sued for this?

Got a letter in the mail today stating he would no longer be my Dr. because I expressed dissatisfaction with his and/or his staff 's services. I don't know what he is talking about. Perhaps he felt a personality clash, If so, it was his alone. I can only guess at why my dismissal came about. Are there laws to protect patients fro frivolous actions of this kind? I sent him a certified letter asking he forward the specific reasons for the action. He also states it is essential that I see my new Primary Dr. as soon as possible. That seems to imply he KNOWS I need medical attention. Please contact me with any questions you may have. I realize this imay NOT be malpractice, but, would it fall under another category; such as ethics & responsibility? Would I be able to sue? There are too many details to but in the allotted space.