Armour Thyroid side effects

My doctor prescribed Armour Thyroid to me to help me lose weight; he did this without taking a blood test. My thyroid was perfectly fine when I began taking it. I took it for three weeks, but didn't like the palpitations and weird things happening to my heart so I stopped. Since then, about two weeks ago, I have had horrible muscle cramps in my upper back, neck and shoulders. I also have pain in my right arm which I am assuming is a pinched nerve from the muscles. Any ideas what to do?? I can't take the pain much longer.

I had a series of racing heart events for a week and went to my doctor. She said it was probably stress and my heart was very strong. They stopped. I went for thyroid tests. My tests indicated I was well within the safety range. I ususally see a woman doctor who works with her husband, but this time I saw him. He said I was hypothryroid and if I did not take Armour, I would be at a cariologist's office. I got scared. I knew my numbers were good, but I caved. I started on 1/4 gram for a week and then to 1/2 for a week and then to 3/4. On my second night of 3/4 I was awakened 5 times with racing heart. I called my doctor and he told me stay on two. I questioned him as to whether this was appropriate for me and he said, DEFINITELY. I decided to withdraw. I cut back my meds. One night I woke up with a racing heart that gave me a nose bleed and I was very scared. Two nights later I woke up with a racing heart that scared me to death as it was going so incredibly fast that it shot down my left arm. I was afraid to go to sleep and started not being able to sleep. I final reached crisis and did not know what to do. I got in touch with my regular doctor who said I did not need the meds. This was corroborated by another doctor. I have not yet spoken to the doctor who misdiagnosed me and came close to causing a severe heart malfunction for me. I will not return to that doctor and will never even consider taking such drugs again.
I was clearly overdosed.