Help!

I really like this guy but he's like 3 years older than me! We were texting for ages but now we don't as much😞 I texted him yesterday and we were talking for a while but he just doesn't seem interested. What should I do I really like him and for a while I thought we might turn into something. Anther this is though he's finishing in my school in 3 days then he's off to college I feel really emotional over this cause I'm not going to see him as much.