As a 21 year old female who went through all these kinds of emotions not long ago, you’re over reacting. Give it a day or two and if he hasn’t snap chatted you back, send him another snap with something flirty or cute like “haven’t heard from you, still alive?” Or idk whatever fits your personality. Maybe ask about his dog, or go for a walk and snap him his house back. Honestly, he’s just being a teenaged boy. Some friend probably told him he snapped you too much and he got self conscious about it. Or something similar. And if he really doesn’t like you, you’ll know after a little bit. And it won’t be the end of the world. Keep your head up girl! Don’t stress over the little things!