How to talk to my crush??

So I’ve had a crush on this guy in my class for about 2 months now who apparently likes me back. We talk every night on Snapchat but recently I feel that I’m boring him and he doesn’t even like me. I send him streaks and he replies with a selfie so I send a selfie back and it just results in us sending each other random photos back and fourth without actually talking. I get the feeling I’m annoying him when I talk to him but then he’s the one who starts the conversation with me so I’m really confused. I wanna be able to talk to him properly without sounding boring or annoying. He also wants to call me sometimes but I make up excuses because it makes me really anxious and scared like I’m gonna just make it awkward. Any suggestions for what I could say? I don’t wanna say things like “how was your day” or “how are you” because after they’ve answered, the conversation just ends and we end up having nothing to say. Any suggestions would me much appreciated xox