Extremely long dream interpretation help?

well last night i had a dream and when i woke up from it it totally set my entire mood the the day and it really sucked i felt so miserable. in the dream i was with some friends and we were in this like house or well we were like attacking it sort of? (it only gets weirder) there were like zombies or something inside the house and i was going through and shooting zombies and completely pointless meaningless stuff and then my dream sort of changed into another dream it was still the same dream uninterrupted but it changed a girl ive known for around 5 years was confessing her love for me and i found myself feeling the same. ive never had any real life feelings for this girl and i dont now. ive always thought she was extremely attractive but ive never liked her. but in my dream it was awkward and it was tender and it was real. and when she told me this we were in a room that seemed to be modeled after the room i stayed in when i was a kid at my grandparents house it had 2 beds in it and after she told me about how she felt and after i told her how i returned the feelings we kissed and then i was like rubbing her back or something and we fell asleep and when i woke up she had to leave and there were other girls from my grade (extremely pretty ones) in the bed next to ours but they were sort of there like i didnt pay any attention to them and now that i think about it, it definitely was my grand parents house because i walked out to the kitchen to say goodbye to her and then we kissed again and i woke up and i felt seriously so freaking miserable. im just looking for some insight as to what my subconscious might have been feeling. i am 100% sure i have no feelings for this girl i dont have any feelings for anyone and havent in a while so maybe it was kind of a manifestation of loneliness? does anyone else have any other ideas? and sorry for the length