New Pillow

Have you ever had a hard time sleeping? Lately I've been waking up frequently at night, and worst of all...I always have a neckache in the morning. I don't have the best posture, and it gets to me at night and during the day. I really need a better pillow and can not find one for the life of me. I need something that's flat and firm. Hopefully I'll find one soon so I can stop wasting my money on the ones that aren't helping.