Dont know if you realize this, but essentially you were just replacing what your body makes. In people who are not hypo-thyroid, you produce about 30-35mcg/day.
Supplementing any less than this, you are just shutting down your natural production and replacing it with an external source. My guess is your 35mcg/day just slowed your body's own natural production way down to where it was only producing the small balance.
Pretty much, until you get over 50mcg, taking T3 is not doing anything.
FWIW, I was diagnosed with hypo-thyroid along with my low t. I have tried as much as 50/ day but my blood work looks ideal at 35mcg/day. But could not really 'feel' a difference at 50mcg, and I was on that dose when I first started a few years back for almost 8 months till we adjusted it.