While many pharmacology books will tell you that sertraline reaches therapeutic levels in 7-14 days, it's been my personal experience that it's more like 8-12 WEEKS. Keep in mind that we all react to medications differently and that includes the time in which they begin to relieve symptoms.
In my humble and non-medical opinion, I believe since you are only 20 days into your regime, it is perfectly normal to still be experiencing fluxuations in your mood. Give it some more time and I'm sure that soon the good days will win out.
Peace
Greenlydia
Thanks for the reply.....I believe I am my own worst enemy with constant negative thoughts! :) I'm just very nervous that it won't work this time but I have been sleeping and eating better (I wasn't doing either for almost a month) so that has to be a positive sign!! Right??
Very normal---I had good days and then some really bad ones--yup. It usually lessens and things begin to get normal after a while.