What do these repetative nightmares mean?

Repetitive just means there is something bothering you. The surprise of the deer dying seems to be the big element. The rest seems like a warning. Without more details, I would say that you are developing a generalized fear of things you can't predict. Start by sitting down and looking ahead in life. Make lists, or plans. 1 day, 1 week. 1 year, 5 years. 10 years. Talk with your parents, boyfriend GF about it too. Tell them about your dreams.