@systemlord was pretty thorough. I’ll add that your target dose may in fact be too low so tapering over time affords you the luxury of seeing if new doses correct the side effects you are having without full blown halving your dose. If you truly “want” to target 100-120mg as a new set point then you could just drop it down as @systemlord stated but once there give it some time before making a new decision as to it’s efficacy. A couple months at new new dose level should do it.