I've felt really torn apart after dreams, like when I dreamt that I was gay, and once I woke up I thought I was bi for a couple of days... (No, I'm positive that I'm straight )

I can see how a relationship with a dream character can seem so heartwarming and heartbreaking, but really- only for a day or so.

I don't think you need professional help, and I don't think you're insane. Have fun with Sarah in your dreams, I encourage you- but please, just don't carry that relationship into the physical world!