5 hours sleeping on the couch

I was so tired yesterday that I fell asleep on the couch for 5 hours without hurting my back. Yesterday morning, I got up at 4, went to work with the feeling cranky maybe because I didn't have enough sleep, I got off work and went back home. As soon as I was inside the apartment, I went ahead to our closet and put my house clothes on. I lit some candle lights in the living room which makes me help to relax. I was feeling comfortable on our cozy couch that I fell asleep real quick. My husband told me that I can sleep and he wished, he can sleep that long too but he can't his back will be in terrible pain.