Thank you for your question.
In this instance, you may wish to speak with a personal injury lawyer about a possible medical malpractice claim. Even though it happened a year ago, under New York law, the statute of limitations, or time to file a claim in such a case, is 2 and 1/2 years. The statute reads in part:
"A medical malpractice action must be brought within two and a half years from the act or omission complained of or from the end of a continuous treatment during which the act or omission took place. N.Y. C.P.L.R. § 214a."
In order to prove a medical malpractice claim, a plaintiff must successfully prove:
1) You were owed a duty of care (this is easy, as every doctor/hospital/doctor's office, etc. owes a patient a duty of care)
2) The accepted standard of care - What a similarly qualified medical professional would do under comparable circumstances
3) Injury -What injuries you suffered as a result of not getting the correct diagnosis. It is sometimes possible for a doctor or medical professional to be negligent, but if there was no injury as a result, there is no claim for malpractice
4) Proximate Cause -It has to be established that your injuries were caused by the negligence
of the medical professional(s) treating you, and not some other reason.
5) Damages (This can be things like physical injury, time missed from work, future medical expenses, etc).
Many of these things, such as establishing the standard of care and your injuries, can and typically do require the testimony of an independent physician/expert witness.
Personal injury lawsuits like medical malpractice are typically taken on a contingency basis, though - so if a firm takes your case, they front all the costs and expenses, and you only pay if they recover money.
Also, you may want to look into filing a complaint
with the Department of Health against the doctor who gave you the improper diagnosis.