Hi i have just come off Zoloft for this reason, i was only on it for less than 2 months.
Everyone is different but i would lay awake at night for many hours and sometimes not sleep at all. I am now starting to take Cepramil which could either have the same effect or make it better... i will let you know
Also i had to take sleeping tablets, but i do not recomend these as it does make it difficult to get up early for work, plus they are quite addictive, its worth trying different meds to find the right one for you.