A terrible nightmare

It was around 6'o clock in the morning, my phone rang deafeningly, which nearly gave me a heart attack! I woke up feeling so exhausted! My phone was on the table opposite to my bed, I went to answer the call but it stopped ringing, I got so annoyed, I didn't want anybody to disturb me again, so I switched off my phone, without checking who called me! I went back to my bed and soon I drifted off into a troubled sleep.
I suddenly woke up, trying to breathe hard and I tried to look around but I couldn't see anything! I couldn't even come to a decision that if I was blind or a place I'm apparently in is that dark. I was so anxious, my sweat was running down my cheeks and I was feeling pulsing of my blood racing through my veins. I tried to wake up, but I lost my balance so I fell down and my head hit the ground really hard but I managed myself to get up but a sudden burst of pain rang through my leg, I screamed loudly, tears started to roll down my cheeks. I gentle touched my leg, to feel what happened as I couldn't see anything, I felt like there was a deep cut in my leg. Suddenly I heard a melodious music, I had a feeling that I have heard it somewhere before then I realized it was my...my phone ringtone, I felt like the sound was coming from my behind, so I turned around, I saw a small light coming out of the corner, I was relieved, I felt like my life came back to me, for couple of seconds I was beaming with joy realizing that I can actually see but soon I realized the reality that I am in a place where I've never been before. I quickly crawled towards my phone, well I thought it was my phone at that time. I took my phone in my hand realizing that it was fully covered with blood but I didn't care at that point, I even forgot that I had a horrible pain in leg. I quickly answered the call without seeing who it was, there was a silence for couple of seconds, and then....