I found that keeping a journal of how I felt everyday especially the first few months after treatment really helped keep things in perspective and it kept me grounded so my mind wouldn't go crazy.
I also would also listen to music or white noise and even sound frequencies in the 432 hz kept me asleep longer. I bought a good pair of sleep headphones to be comfortable.
I also went for massage therapy to keep tension levels down as I would be very tense when waking up from sleep. I started to grind my teeth because of all my anxiety.
Its funny as I also felt left hanging after treatment and all the adrenaline I had to get me through treatment was suddenly gone and felt very isolated. When I was first diagnosed I was given some anti-anxiety pills and I renewed this prescription after treatment for days when I could not let go of things enough to get into a good sleep.
It sounds like maybe this is something you might need to discuss with your GP. Even now a year out of treatment I have bouts of anxiety. If I'm feeling it come on or I feel I need a bit of help to get over the edge like feeling a take these piles for a few days and then I'm ok again. There is nothing wrong with asking for something to help. It's doesn't mean you are week or in crisis. It just is a part of this journey. Don't suffer!!
Try different things but in the end don't get down on yourself if you need help.
All the best.