Do i have hyperthyroidism?

I have thyroid problem , And i have given blood for the test sometimes the t3 are less and sometimes the hormones are high. The doctor are not sure if it is hypothyroidism or hpyerthyroidism. I also did altrasound to diagnose the problem but the result was negative. Now my doctor advised me to do nuclear scan for hyperthyroidism.I have symptoms:
1-dry skin
2-palpitation
3-sometimes constisipation
4-can't tolerate high temperature

These symtoms shows both hyperthyroidism and hypothyroidism. I am confuse and worried about my situation. And I have read that nuclear scan can cause permenant hypothyroidism after 1 year if a person did it.(nuclear scan).

If any body have something to advice me or something to discuss please post it.