Pain In The Head, Blurred Vision And Palpitation. Feeling Tired And Cold. Family History Of Thyroid Problem And Cancer. Any Advice?

every few weeks I start with a pain in the front and side of my head on the left, quickly my vision starts to go, my heart beats really fast and I cant breathe. Then my vision starts to clear after a few seconds and everything returns to normal, except Im left with the headache and a pain by my heart.
Meanwhile I am permanently tired and feel cold all the time. Anyone who touches my arms always say how cold I feel to the touch.I work full time and have to have at least 9 hours sleep at night to get through the following day. I sleep most of the weekend to recover from the week.
My doctor sent me for blood tests which his receptionist said returned as 'normal, take no action'. I wear glasses but only had my eyes tested 6 months ago. My mother has a thyroid condition, she is coeliac and had heart surgery to remove extra electrical pulses from her heart. My dad had cancer and died of a heart attack.
I am 49, I do not drink alcohol or smoke. I am vegan.