Nightmare or Missing ?

To A Jasper
Last Night, I dreamed and I woke up because I had nightmare. I dreamed to my ex-girlfriend. The story is about I came back to the past in a period of time when i study in high school. I came to high school with my mom, brother and my sister like everyday. I wear senior high school uniform everything same the past but my hair was long hair like now. I walked into this school and everything are white. I felt shock when I saw my ex-girlfriend waiting for me and see her watch like everyday in the past. Her face look worried because she hurried to go to clean classroom number 510 and then she shouted and ran to me, catched my right arm and invited me to ran with her. When we arrived my classroom she ordered me to clean the blackboad infront classroom This day isn't my day to clean classroom so I said to her "NO". She said to me "You must do it now!". And she picked a bloom, mop and something behind her hands to me. I accepted her to clean because If I said "No" again, she must send somethings behind her beautiful hands. when I clean that room nearly to finished. She jumped in the way I clean room finish and picked a chock(like a pen to write at the blackboard) draw heart in my school uniform. I felt angry but I find the way to do like this so I picked a chock to tried to draw a pig on her skirt. She felt like me too so We made this room dirty again, draw blackboard and school uniform together. When we tired we stopped and sat together.She hug and kissed my left ear and said to me softly "I love you" and then she left me before she left she said "Waiting me in this room. I'll comeback to see you" and then I woke up and tired!. I don't know myself. She broke up me 2 years ago but I don't know why I missing her. I dreamed to her manytimes. I have new way of life and she had it too but why?
Can I get some advice about this? Teacher