Hypothyroid medicine dosage. Measures.

I have been diagnosed with hypothyroidism 3 yrs ago tsh was 4.45 and dr gave me levothyroxine sodium 50 mcg for 10 days and stop medication but then my tsh went 10 and put me on 75 mcg and I was taking and used to see dr and I have infertility as well and my ivf dr changed my dose as few months bck to 100 again as tsh was 3.25 and then my tsh went to 0.8 endocrinologist told me to stop medication but after stopping medication my tsh is now 8 and endo dr told me to take .25 mcg but my ivf dr said it is less and advice to increase to 50 mcg what should I do my weigh is 67 kg and I lost 2 kg with diet and exercise but gained back and hieght is 157 cm plz tell me abt what dose should I be taking and why I am not loosing weight Despite taking all measures.