Welcome to HCM,
You are having Hypothyroidism
and taking Thyronorm
75 Micro gm( Please note this not in mg) that is small dose and your TSH level
is not very high so this should be adequate.
You need to take Thyronorm according to your Physician advice your TSH is You do not need to insist for change of dose of Thyronorm as your doctor knows best.
You weight gain could be due to your diet and lack of physical activity.There are other possibilities like metabolic syndrome
and polycystic ovaries
There could be some anxiety as cause for insomnia, please discuss with your Physician and if you are TTC there may be some other cause both partners should visit Gynecologist and get proper investigations to know the cause and then treatment may be given for that also.
Wish you good health and good luck.
Please take care