The thought of growing up makes me feel sick?

I'm 19. I've been dreading growing up all along, I was never one of those kids who couldn't wait to get older. I stopped looking forward to my birthdays after 16. Anyway the rest of high school was really fun, but now it's over and I'm in college and I have a real office job that I work full time. I hate it. I just feel like I'm so old and grown up with all this responsibility and no fun. I cry all the time about it and have even gotten so upset to the point where I've gotten sick. I know this isn't normal but it just scares me to death to get any older.