Confused over symptoms

.I had my thyroid removed on Oct 9th started my synthroid Oct 15th...was fine up until Nov.17th..then it was awful..constant all day anxiety attacks..pounding heart,chest pain,nausea,vomiting,diarrhea, shakey (shaky), hot one minute,freezing the next, muscle twitches..thought I was dying. finally last night Nov 28th went to ER..was told my TSH was 19.4 , called my endo doc and she said that meant I was hypo...confused because all my symptoms point to hyper. She is ordering some special hormone test tomorrow. Has anyone else had this happen to them and what was the problem.
Thank You