have you ever felt that way?

Have you ever waited all day long for him to reply the message you sent him, or hoped that he'll remember you and msg you first? Have you ever stayed home instead of going out with friends hoping that he'll come online? Have you ever spent days and days making plans about you two, knowing deep in yourself that nothing of that is going to happen? Have you ever felt like you can't breathe when you look at his pics, cuz you want him to be right next to you so bad? Have you ever felt like this for someone you didn't even met in real? Is this even possible, or am I just getting out of my mind?