citalopram - changing dose and side effects

Hi everyone I just wondered if when slowly increasing your dose of citalopram it has made you not able to sleep, more anxious and your head foggy and not feeling like you are there?
I started on it about six weeks ago and took 10mg but I had a strong reaction and felt so anxious so GP told me to 5mg so I did that and was fine, I then took 10mg for the past 3 weeks as was
Too scared to go onto the 20mg dose I was originally prescribed. I did finally do it three days ago and now as I take it at night I cant sleep? Is this because I am just getting used to it or should I not
Take it at night? I really don’t know if it’s the drugs making me feel this way or my anxiety as it is really acute at the moment?
Any advice would be brilliant
Thanks
Hellbelle