nightmares and dreams

what do they mean? sometimes the meaning is so transparent and other times I just wake up to "what the hell was that????" I don't know why I always seem to be a child in my dreams and why I always seem lost . I wish someone could tell my why I have this recurrent dream/nightmare or why I can't go back to sleep after I have a nightmare. My daughter who is 8, is the same...she is fearful and full of anxiety(its hereditary) and can't go a night without painfully searching for me in the middle of the night .Like I might just disappear. maybe she knows something I don't.