Milk supply plummeting and I'm pretty sure it's the cough drops

I've had an awful dry cough for a couple of months now after a bout of what was probably RSV (thanks, daycare!). I literally can't sleep without a cough drop because when my body relaxed my throat gets buttered and I start clothing and hacking and cannot sleep at all. For the past few weeks I popped a honey cough drop in my mouth before going to bed which has helped tremendously with no impact to my supply but the past few days my supply had suddenly gone from 25 oz/day to 22 to 21, and as I wake up for my MOTN pump my breasts currently feel empty. I used to make 8 oz my MOTN pump and right now they feel like I'll maybe get 3 oz.

And I'm sending if it's because when I asked my husband to get me more cough drops he bought a different brand which I've taken for the last three days. I suspect there's more menthol in them than my usual brand. I'm going to run out today and buy my normal brand (and maybe some Oreos) and cluster pump every day this week to see if I can build my supply back up.

I hate how SENSITIVE milk supply is. It's so goddamn fragile considering it's how I feed my baby!!

I'm also annoyed at how long this dry cough has lasted. If anyone has advice for that (besides a humidifier because we sleep with the door open so that won't work) I'm all ears.