There are many reasons why you may be feeling ill - Not on the change of dosage long enough - adrenal issues - pooling Free T3 and other reasons.
With only a TSH lab to go by it's too hard to say.
But why the change in the first place? If we go by just TSH alone and you say you felt fine then a med change should not have been done. You still fall into the normal range with a .4
AACE guidelines are .3 - 3.0 - so you are low but still normal. No change would have been needed. At least in my thought.
Hi.
Have they tested your FT3 and FT4? Do you know what these are?
Are you on thyroxine? Maybe you could ask your doctor if you could try armor or cytomel (T3). Some people feel better on these than on just T4.