Im 19 and have been told there is a strong chance i have hyperthyroidism , Any advice?

i went to the doctors the Other day for headaches anda new prescription of the pill my bp was 129/89 and my pulse was129 beats per min, my doctor suggested that i might have hyperthyroidism , ive done research on the net and realized i have loads of the symptoms , fast heart rate , unstable mood, joint and muscle pain , weight lose , increased appetite etc also my periods have been all over the place sometimes even 6 weeks between each one so i went bac on the pill and even then im comin gon later and my periods are 2 days long . i tried to shrug it off and forget about it , but for the last 2 days ive had really bad chest pain and unable to breathe deeply is this something to do with the hyperthyroidism? i have a really bad fear of doctors and hate going but i don't know what to expect with hyperthyroidism , does it sound like i have it ? if so what should i be looking out for ?