I don't want to be rude. I just want to comment on my experiences with Melatonin, chronic insomnia/anxiety connection, and communication. Considering that everyone is different, my sleep specialist told me how to take Melatonin:
• take it two hours before I expect to fall asleep
• it doesn't work "as needed"
• it has to be taken at least 6-8 weeks to take effect
• don't exceed 6mg/night

I appreciate doctors who are open to a variety of resources. Also, the sleep specialists told me that meds such as Belsomra, Lunesta, and Ambien are not effective for chronic insomnia...in a recent 2021 study, researchers indicated that the 3 main sleep meds help a person fall asleep 6 minutes earlier than the control group.
In my case, Belsomra did not keep me asleep--1.5 hours and then I was awake. On Ambien, I sleep-eat, sleep-drive, sleep-text, sleep-shop...you get the point. Lunesta was ineffective.

My psychiatrist referred me to a Cognitive Behavioral Therapist and we're working on an individualized plan for me related to the chronic insomnia/anxiety connection.

Talk to your doctor. Recently, I had the guts to ask my primary physician to talk to my endocrinologist. That was a very effective intervention. And I asked my psychiatrist to talk to my Spravato provider/ Pharmacist & vice versa.
Communicate! What a great concept!