Nighttime Anxiety

I have circadian rhythm disorder (a branch off insomnia) and it causes me to have a lot of anxiety about going to bed. I always worry that I won’t fall asleep and if I do, I won’t hear my alarm and sleep in really late. I have to be up at 7:30am everyday for work and there have been instances where I fall asleep and I’ll miss my alarm and wake up at 8:15 which rushes me to get out the door and get to work by 9. What can I do to alleviate this anxiety? I follow a good bedtime routine and take melatonin supplements, but the anxiety sometimes causes me to psych myself out and keeps the melatonin from working. And tips?