Welcome to HCM
In your case if you have hypothyroid you need to take thyronorm
supplimentation and this is the same chemical produced in our body so there are no such side effects yes if excess dose is taken for long time it will have same fetures as thyrotoxicosis
or kidney pain
may be because of some other problem or disease.
About the TSH value in two different place, you should be examined clinically by endocrinologist
and take a decision about drug to be continued or after a gap you need to retest FreeT3,Free T4 and TSH.
After the result one can decide how much supplimentation is required.
Good luck to you.