Meeting after six months

I saw this girl for the first time in six months and we both liked each other a lot when we used to meet regularly, but the chemistry and attraction we had are gone, it's like we don't know each other. She told me that she liked me after three months of texting, we didn't face time or call, we were both too shy. The moment she walked into the room everything was off, it was like there was a wall of unsaid between us, and before we had both expected to be instantly attracted like we always were, but for some reason, we both felt nothing. It was like she was a stranger who I knew but at the same time, I didn't. I'm really dismayed because after a while I started to feel that attraction again and realize that I liked her, but she didn't feel anything for me, what do I do?