What happens when you take thyroid pills and your body doesn't need them?

I was "diagnosed" hypothyroid by an endocrine doctor with only an elevated TSH of 4.6 with normal T3 and T4 levels. I had all the classic symptoms which my family doctor was convinced was due to depression and not a thyroid problem. As time went on I was slowly given a higher dose of Armour thyroid until my TSH was within "normal range" and I only felt worse and worse. I would almost feel like the pills were making me have a thyroid problem, if that makes any sense. So the other day I just happened to miss a day and couldn't figure out why I felt so good. I recently had started an anti-depressant but didn't think that was it and then realized I had forgotten to take my thyroid pill that day. I have been off it for 4 days now and I can think clearly and have a lot more energy then before but have found myself incredibly tired in the AM upon waking and PM prior to bed (which isn't a bad thing)? Has anyone experienced a misdiagnosis as being hypo and then feeling worse when it could have been depression all along since they have the same exact symptoms? Thanks.