Advised Neomercazole, Thyronorm For Hyperthyroidism. Getting Heart Beat Continuously. What Is The Reason ?

hi am AAAAA, i am sufferring form hyperthroidism form last 8 months .when i tested my blood for the first time my tsh was less than 0.01mU/ml after that i was suggested to take neomercazole 20(2 tablets daily) since then i hav been doing blood tests regurarly and my tsh levels grew and accordingly neomercazole was decreased to neomercazole 10 (2 tablets daily) but now my TSH levels are too high i.e 45.90 mIU/ml and now am suggested to take neomercazole 10 (1 tablet daily) and thyronorm 25mcg (1 tablet daily) and am taking these tablets form last 8 days but now am getting high heart beats continuously for 2-3 hours form last two days and i feel as if am having a lot of pressure of something so may i know what might the reason ????? also 8 months back i had vitamin deficiency so i was given 5 injections of vitamins and was taking Hosit plus for 4 months. now i dont take any vitamins. I dont have any other diseases and my age is 24...........please help