Hypothyroidism in second trimester

Hello girls , I need your help and support.. I'm now 18 weeks and just through my regular blood test I recognized that TSH is increasing day by day ( i had the test before pregnancy and it was 2.8 , i did the test again at 7 weeks of pregnancy and it was 5.2 ,i repeated the test last week and it becomes 7 ) normal TSH range is maximum up to 4.5 ...now i was adviced to see thyroid glands specialist especially that its effecting my body weight ( i did not yet gain weight at all during pregnancy) and i have insanely increasing heart beat some times...

Now i will be obviously taking pills for regulating the heart beat and also thyroxin pills for controlling the TSH and im soo worried about my baby .. any body has experienced such problems , any advice , support .. thank you