No, Write every dream you have in a notebook. Go over the dreams each day, see if there is a connection to one thing. (Such as clowns, zombies, high buildings.) if you notice a small connection, that will result to your main fear. Most people are afraid to die though.
Does sound like a combination of anxiety and hormonal changes; neither of which is that uncommon at your age. And this applies whether you are male or female. If your worries about death become a full-time obsession, pre-occupying your thought throughout the day, you may consider talking to a professional and finding a reason behind that.
This is the natural feeling if you do not know the promise of God in the Bible. Romans 6:23 says, "For the wages of sin is death, but the gift of God is eternal life in Jesus Christ our Lord." All of us will die (eternal separation from God) but to those who repent from his/her sins and receive the forgiveness of God and accept Jesus Christ as his/her Savior and Lord will be saved (eternal life in heaven). We will not be afraid to face death if we have faith in Jesus Christ the only way to be saved. He died for you and paid the penalty of your sins which is death. The only thing you need to do is to accept Him, Jesus Christ the only Savior (John 14:6).
Pray to god so he can help you through this, I went through the same thing except I would dream that my family was getting killed hopefully you will get through this. If this doesn't help then talk to your parents or an adult that's close to you =)