Hi Janey, I wrote a response to this earlier but it must not have worked for some reason.
I suffer from severe anxiety and it also got progressively worse during the earlier part of my pregnancy and at around your stage (now 26+5) I was referred by my GP for CBT to avoid it escalating. I also deal with the insomnia inducing type of anxiety and it is so much worse when you are pregnant.
As part of my CBT the first thing I have done is something called Progressive Relaxation Therapy. It is very simple and not time consuming and it has really helped me to rest better.
Its as easy as a few body tensing and releasing excercises (kind of like a self massage) and stretches and listening to a soothing voice guiding you through it (I do this with a recording). It is not meditation, but more about releasing the stress from the muscles in your body so your not so on alert from the worry and can relax better.
It has really worked for me to help with sleeping and I do it once a day before bedtime. I just use a very simple one on YouTube:
It sounds silly but if you are open to it, it does really work. The video I linked is very simple and there are lots of different types for different people depending on how into it you want to get:
The second one is very good too and actually uses the muscle tensing techniques so you really get more out of it.
The best way to do this is sitting on a chair but in a relaxed position or on the bed also in a relaxed position.
Just don't do any tensing of the stomach muscles while pregnant
I hope this helps and if it isnt for you then I hope something else helps 