Hi there.......I recognise your problem as I've suffered the same myself,having been under medicated for a long time.When my GP finally agreed to raise my Levo although somethings improved my joint pain got worse.Eventually I was referred to an understanding Endo who was willing to prescribe T3.( a conversion problem) My GP has accepted prescribing it for me too,though was surprised at the cost on NHS.
My joint pain didn't disappear completely but did improve.Taking myself off bread,cakes,biscuits etc also helped.
I have tried Armour( self purchase) which is OK butI have approached my GP about it and have given him info about getting it on a " Named Patient Basis" and he was going to have to consult his team......so far I've heard nothing,so not looking good.
However,at the moment I'm currently prescribed 75 mcgs Levo and 10mcgs T3 but today going to raise my Levo back to 100 mcgs.( my nails were much stronger on 100mcgs Levo before adding T3) but Levo was reduced in order to add T3 .
I recently read a newspaper article by Arlene Phillips who was suffering joint pain and recommended taking GoPo Rosehip capsules and said that her movement was much improved.( 120 capsules £17.99 )
I have purchased some on line and they are definitely helping me,but it is early days( only been on them for a week) Arlene reckoned she needed a month for a great improvement.
If you have a conversion problem then some T3 may be your solution and a good Endo would recognise that.
However,I think it is a lot more difficult to get NDT prescribed for most people as it's not licensed in UK.If you have private health care it might be worth enquiring.Sorry for the long post ,but hope info on my own journey might be of help.It certainly takes a lot of trial and error to get sorted not to mention the time involved....good luck.