Had Thyroid Removal. Have Dizziness. Taking Levothyroxine. Worried

Hi I ve had my thyroid completely removed 2weeks ago I did have an overactive thyroid for 9years from age of 14, the surgeon could only save one calcium gland and that is bruised at the moment so not working I ve got a very low calcium I m on 14 calcium tablets aday 1500mg each one, they got that stable but its still a little low then normal, ive had this light headedness since I ve had my op I know I m under active now I m taking 125mcg of levothyroxine and 20mcg of liothyronine for the under active thyroid, I don t know what is causing this light headedness/ dizziness I never had it before my op was healthy except having an overactive thyroid.. It s completely getting me down now been 2weeks since my op I can t drive or even function normal day to day things, I m sleeping loads tired out feel down all the time.. What is causing this light headedness is it to do with having low calcium or the under active thyroid.. My thyroid specialist not worried about it but I am I can t do normal things can t drive my car feeling like this.. Can you give me any answers why I feel so rubbish.. Thanks Kaye