Sertraline

I have been on Sertraline (Zoloft) for PPD for seven weeks. I started out at 12.5 mg and have slowly worked my way up to 50 mg in 12.5 mg increments. I have been taking 50 mg for 6 days and have noticed an increase in my anxiety and just feeling generally weepy. I've also been having very  vivid dreams that wake me up and get my anxiety going so then I have a hard time getting back to sleep. Does this mean I'm on too high a dosage? Just looking for some encouragement from someone who has or is dealing with these meds. Thanks!