This looks like possible secondary hypothyroidism, in which case the TSH test is useless. As your T4 and T3 are both low, your TSH should be high. I suspect, in this case, that your t4 and t3 are low because your TSH is low rather than the other way around. It looks, from your results, that your pituitary gland isn't producing enough TSH for some reason and this is resulting in low t4 and t3.
If this is indeed the case, your doctor needs to ignore your TSH and go purely by symptoms and free t4 and t3. Please do ask for this to be investigated if they insist on reducing your meds.
As has been said before, you need to argue your case. Your t4 and t3 are low so you need more medication. If they are going by your TSH and not looking at your t4 and t3 they are being negligent. It is dangerous to let your levels fall so low purely because your TSH is low. There is some other reason for your low TSH and it is certainly not too much thyroid hormone. TSH can be affected by many other things so should not be the only test for thyroid. T4 and T3 are far more important and accurate indicators of your actual thyroid status.
I hope this helps