How do I keep an LDR alive?

My bf (18M) and I (18F) are entering an LDR, he will go to a different country for his college and I'm in my NEET drop year. How do I maintain the LDR along with keeping my preperation well? Is there any way i can excel in both?

Is it true that they grow more distant after meeting new people abroad? How can I cope with in case it happens, instead of stressing and worrying?