Agoraphobia & Social Anxiety Support Group
Agoraphobia is an anxiety disorder, often precipitated by the fear of having a panic attack in a setting from which there is no easy means of escape. As a result, sufferers of agoraphobia may avoid public and/or unfamiliar places. In severe cases, the sufferer may become confined to their home, experiencing difficulty traveling from this "safe place."

I would advise not to cancel your main Medicare plan just yet.
Call your doctor's office and let them know what happened. Perhaps they will have some useful information for you to get the blood work done that you really need to get done.
I understand how this situation would make you upset. But, it can be fixed.
Hang in there. Call your doctor to tell them what happened.