Was there a specific deficiency/cause identified which, when eliminated, made them better?

This is 3rd week that I cannot fall asleep without at least 7.5mg Temazepam every night and even though it's the lowest doze, it's not advisable longer. It already shows signs of ineffectiveness, I get very tired and yet I cannot sleep. I don't want to go higher doze.

I did extensive research on all med options . My PCP recommended Mirtazapin, but I have some questions/concerns. Problem is my access to him, let alone a specialist, is limited and slow. This is scary and exacerbates my condition.