Well, that is really awkward for her, especially if it is her first time to dream about that. She'll think about it and she might really get awkward around you. But explain to her that it is only a dream, and it won't be true. Once she stops ignoring you anymore, ask her why she is so affected about the dream.

TBH, I think that the dream only symbolizes that you are close! :))

Kiss her for real! hahaha kidding..yeah, I understand you, it's not your fault...maybe she has feeling for you? omo hahaha well, if you don't want anything, just act normal and give her the time..

hello i hope you would consider my statements..
"my cousin my best friend my classmate and my roommate" are you referring to one person only?
you know dreams are considered by psychologists as wishful thinking, a sign of something bound to happen or the subconscious mind of the person. when we say subconscious this is the state of mind wherein the person is half-conscious of it thus partially knowing but NOT acknowledging it FULLY. so what i am trying to say is if she dreamt of kissing you then maybe consider the thing that her feelings of you is beyond platonic. given the reason that it worries her making her to ignore you only means that the dream seriously bothers her. if it doesn't really mean anything to her then things should remain normal. you'll not know anything until you talk to her for real. try asking questions like say, "be honest with me...blah blah blah.." what do you really feel about the dream or why does it bother you so much if it IS NOTHING IN THE FIRST PLACE?"..
i am just trying to help you not go to the state of getting things blurry. you know if you don't talk things out you'll lead yourself to a lot of doubt and assumptions. this might even put you two in an very very awkward situation :))

i hope this helps :)))
and the only thing for you not to be ignored is to push her to talk it out with you :)))

Omo cute. Kiss herrrr!!!
Onii chan ignores me too...did oniichan dream kissing me?

I understand that you might feel like you've been treated unfairly and she's being silly, but, if you look at it from her point of view, she's not to blame either. Sure, you shouldn't take any blame but that doesn't change that you were in the dream with her. Since you two are so close, she will need time to get over the idea and you should just wait patiently.
Hope everything works out for you
:)