@user1489094655 - it might be worth considering Mirtazipine, as an alternative to Citalopram - it is my understanding that it tackles anxiety as much or more than it tackles depression. I am on it, and whilst citalopram did make me feel nauseated, Mirtazipine hasn't had that side effect for me (just to reassure you).
It would mean coming off citalopram, which I know is not easy, but it might be worth it if it helped.
A couple of things from CBT at helped me:
Mindful breathing - sit or lie in a comfortable position, and just focus on your breathing. Notice the movement of your stomach, up and down, of your chest expanding and contracting. Notice the feeling of the air moving in and out. When a thought or anxiety comes into your head, notice it, acknowledge it, then set it aside and refocus on your breathing.
Intrusive thoughts will happen - I used to worry that I was 'failing' because I couldn't do this meditative breathing without getting sidetracked by my thoughts - but I was WRONG - it is normal for these thoughts and anxieties to come into your mind - you simply acknowledge them and go back to the breathing.
I found this helped me to relax, and also helped me to see and acknowledge my anxieties, to sit with my fears, and then to set them aside and move on.
The second thing was a visualisation exercise. My therapist told me to picture my depression as a huge, dark coloured cloud in my head, then got me to visualise a lighter colour starting at the edges of the cloud, spreading inwards until all the darkness was gone. I found that it worked better if I visualised it as a weight in my head, and visualised it getting lighter and lighter. Either way, doing this for a few minutes helped me to feel the feelings and then get them to lift - it didn't make them go away, or stay away for good, but it was a tool that has helped me to cope when things get bad.
There may be more resources available online - there are definitely self-help books abut CBT, which might help you get through, until you get the therapy yourself.
I hope this helps.