It’s not unusual to feel this type of attachment

In reality of things you can call it attachment and perhaps infatuation but id not call it love. If you only knew him in therapy room and from what you see of him online, it’s not enough. You’ve no idea who he is irl. And age 16-18 is tricky. Many “in love” situations in that age felt like big meaningful things.

Try to move on to make connections with real life people and it’s an excellent idea to process it with a new t!