Possible dumb question

So I've got my cdl, I've got my medical dot, but can I drive if I am on methadone? Regardless of reasons, my question is; could I have a future in this industry? I was told by the guy who owns the trucking school i went to that being on this medication will NOT hinder my future trucking career, I have had SEVERAL jobs (that I've been upfront about my situation with) tell me my cdl is in my hands, it DOES NOT MATTER, come start date I get told I need to do a fitness for duty, due to my drug test, unfortunately these fitness for duties are NOT with doctors that know ANYTHING about my situation, so of course ill fail this...is there a trucking company/companies that will NOT send me for this fitness for duty test? What's the point of my having a medical card, if im just getting sent to one of these things anyway? AND I've been told companies do NOT have to send me to this test, its only a "recommendation from the MRO" What do I do? What CAN I do? Hell ill work for YOU if I just get to freaking DRIVE, thats all I want, im legal and EVERYTHING, its ridiculous, or ami wasting my time here?