Recommendations for sleep specialists/doctors?

Hey, for the past few months I’ve been really struggling with my sleep. I’m having bad insomnia which I thought was temporary but it’s not going away, it’s been almost 6 months now. I never had any sleep issue in my life. I am looking for a sleep specialist that treats insomnia in an organic way….what I mean is that I don’t want to be on sleep medication. For the past few months I’ve been seeing different ones around Plano/Frisco area and all they do is give you 10 mins max and then just prescribe you drugs without even diagnosing the full issue. Any help would be appreciated. Peace.