Citalopram query, alternating between 10mg and 20mg

hi this is my first time writing in a forum ive been on citalopram 10mg for 4 weeks, 7 days ago i was upped to 20mg every other day so 10mg one day and 20mg the next and so on, so my body could get used to the upping, this week about 2 hours after taking a tablet ive started getting rushes through my body,feeling flushed, anxious and then obviously leading me to panic about whats happening, feeling very anxious this week too where as last week i was more positive, just looking for some reassurance thankyou :)