Am I really in love ? ?

I met this girl about 3months ago and since then she has turned my life into an amazing adventure . It feel like when were together nothing in the world matters. Our eyes light up everytime we see each other and when were apart we are miserable . She told me she loved me first. And I said it back . I'm 20 and I have never felt so good about anything in my life . She makes me feel like a better person just being around . Also when we kiss she always pulls away after about 3 seconds before it gets too intimate why is that ? Please help everybody . Idk If I'm confusing lust with love.