I have dealt with anxiety my entire life and when it comes to sleeping it is the worse. Sometimes it occurs in the less expected nights. What helps me sleep is:

1. Try not to overthink "I will sleep early today" or "I will manage to sleep easily"

2. Try to empty your mind before sleeping, ask yourself: "What use is thinking of this right now."

3. Most importingly: For me Anxiety causes me to move alot before sleeping and I believe it is my thoughts who are not letting me sleep, but it is NOT. Try to remain unmoving and for me I will get tired after a while and the thoughts will be gone.

Hope it helps!