I have Hashimoto's, so I'm pretty severely hypothyroid without medication. I have been on Levo alone, and I have been on Armour. Neither one brought significant relief for me.
What has finally worked is taking Levothyroxine (which is a T4-only medicine) AND Cytomel (which is a T3-only medicine). I currently take 125mcg and 25 mcg, respectively. My doctor explained that my body doesn't convert T4 to T3, so just taking Levo did nothing for me - my TSH test was great, but I didn't feel better. He explained that the reason Armour worked a little bit better was that it does contain T3 - but the problem is, because it's a natural product derived from the thyroids of pigs, the medication is only as healthy as the pig it came from, so the amount of T3 provided by the medication can vary. He prefers to use Cytomel so he can independently adjust the amount of T3 I'm getting, and be assured that the amount is consistent.
So, I've been on this combination of medication for about 6 weeks now, and I feel better than I've felt in a decade. Seriously. I have enough energy to exercise, I'm sleeping well, my skin looks better, my hair isn't falling out, I'm losing weight (hallelujah).
I would encourage you to ask your doctor to order several labs, if s/he isn't already: free T4, free T3, reverse T3. The TSH test is just about worthless, because it doesn't even measure the amount of thyroid hormones in your blood, it just measures how much your pituitary gland is calling for. If your T3 results are low, but your T4 results are good, that would indicate why you don't feel well, and indicate a need for a T3 medication to be added to your medication regimen. If your doctor is unsupportive of any of this, I would recommend going to a D.O. (which is a medical doctor who is also a naturopath - for whatever reason, they seem more interested in making sure you feel better, not just throwing medication at you and shooing you out the door).
ETA: Almost forgot! I get much better results taking my Levo at night, just before bed (3 hours after dinner). Then it has all night to absorb, AND first thing in the morning I can have my coffee! I take my Cytomel in the morning.