SERM dose too high, high LH pushed up E2. When you stopped SERM without tapering, suddenly HPTA sees the high E2 and shuts down. So attempt at a restart fails there.
Your T3 and T4 is mostly bound to thyroid hormone binding proteins [TBP]. With varying levels of TBP, one really does not know the status of the active fT3, fT4 levels. You need to test TSH, fT3, fT4. Note that hypothalamus cannot see TBP bound T3 or T4. So if TBP is high, T3 and T4 can be high, fT3 and fT4 can be lower and the hypothalamus causes TSH to be elevated. And if rT3 is high and blocking fT3, same story. See if the new sticky ‘thyroid basics’ is helpful.