Looking for psychiatrist/therapist in Clear Lake area for my nephew

Hey y’all, my nephew (M 16) is going through a rough patch and is having some difficulty processing his emotions. He has been asking to get some help from a psychiatrist or therapist but his parents haven’t had much luck due to providers not accepting any more patients. He’s asked me if I could help him find one, but I don’t know where to start. I know he is on Aetna insurance. I would love some recommendations for him because it hurts me to see him in pain, and I know seeing a therapist helped me tremendously. Please let me know if there are providers you would recommend so I can send them to his parents!