I agree, it takes time. It can be so frustrating to feel so awful and not see the light at the end of the tunnel.
Aside from the treatment you are on at the moment, have you had other things checked out eg: ferritin (iron stores), Vitamin D and B12. These 3 are ones which doctors rarely if ever check and a lot of people, particularly thyroid sufferers can be low in some or all of these. Low ferritin and Vit D would be the most common. for all 3 your ought to be at the higher end of the lab range. A lot of doctors will be happy for you to sit at the bottom and of the range, so long as you are 'within range', but you will feel a lot better when they are at the higher end of the range.
Another thing to look at at some point, if you keep feeling tired, would be your adrenal function, which can make you feel tired, foggy, forgetful. Vit D is very beneficial for a well functioning adrenal gland too.
Hoping you feel better as time goes on