I M 31yr Old, Trying To Conceive Since 2yrs, Having

I m 31yr old, trying to conceive since 2yrs, having hypothyroidism, initially on 50mcg T4 daily my TSH was 0.5, so was advised to reduce dose to 37.5 mcg daily. Repeat Tsh after 2 months of dose change and also changed from eltroxin to thyronorm.... Is 5.87, normal free T4 values. And previously normal level of prolactin(7) has risen to 30... AS I M TRYING TO
, they ve asked TSH below 2.5, pls suggest dose
Thank u