citalopram 20mg to escitalopram 10mg

hi folks

ive been having a terrible time of anxiety just lately feeling really awful dp/dr been terrifying felt like im losing the plot i went to gp 5 weeks ago for a blood test and it came back as slightly under my iron levels so he started me on a course of ferrous sulphate 200mg (iron tablets) for a month i came away from the doctors worrying like mad that it was something terrible like i was dying of something this lasted for a week i even went out and bought a set of scales to check that i wasnt losing weight i was like this all week panicking at the end of the week was when my anx started again after being 100% for a good few months on cit 20mg.anyway dr decided to up cit to 30mg then to 40mg over the space of a few weeks but i was no better so i went back a week later and asked for my meds to be changed to escitalopram as i thought a change of meds would be a good idea so he agreed and put me on 10mg of escitalopram last week (sat) past few days i have felt absolutely awful dp/dr been horrific stomach churning loss of appetite the works been very frightened can i be on withdrawal from cit possibly even though im taking ecsitalopram or could this just be side effects of escitalopram also how long do escitalopram take to work sorry for waffling i just need someone to share this with

thankyou