Yep insomnia is going to be brutal, there aint no way around it, there really isnt.
Melatonin, meditation and magnesium oil will be come your friend!
Remeron is a doddle to withdraw form compared to Lexapro so you are doing the hard one first which is a good choice! Just accept the insomnia, its a lonely walk, but acceptance is half the battle I found.
I wouldnt be looking t ingesting more chemicals at the moment, but your call