Pillow recommendations

Hi, I just started your program and I’m hopeful for the first time that I can improve my posture and reduce the pain in my neck/shoulders/upper back that is causing my daily headaches and the way I look. I was wondering if you could recommend a pillow or atleast the type of pillow that is best for my kind of issues. I wake up almost every morning with a bad headache usually behind my head and neck. I know it is caused by my posture and neck tension. I was just hoping to get some kind of relief while I’m waiting for your program to help me. Thank you for any suggestions.