Hi Brandon,
She was most likely in your dreams last night because you have been thinking about her quite a bit for the past 2 months.
Oftentimes, when a person thinks about someone a lot and there are intense emotional feelings attached, their subconscious will catch on to that and will cause them to have dreams about that person at some point.
Unfortunately, all those emotional feelings have only become more intense with time and this may be the reason why you are so scared whenever you are around this girl.
She stares at you and you become shy and nervous because you have most likely built her up in your mind as the most perfect person.
That sentiment would make you feel very insecure about yourself because you just won’t feel as though you can match up with her.
In other words, you have most likely put her on a pedestal and find it hard to see her as anything else but perfect.
As long as you hold her on such high regard, you will most likely keep getting shy and nervous whenever you look at her or she stares at you.