I'm in love with a girl I met 20 days ago. And I'm freaking out because I haven't had feelings for anyone in over a year. Idk what to do...?

We met the day she broke up with her bf.. And I was recently single as well so we started talking, and a few days after talking we were into flirting and then met up and started going on dates and getting physical etc... And yeah we like eachother, but idk. I haven't felt this way in so long. I know I love her, but I don't know why. And I don't want to tell her because we are just waiting for the right time to be together (her idea). And im worried about getting hurt now because of my feelings.