I know exactly how you feel!
When you are in love, you might want to spend all your time with him, right?
I'll be direct with you, okay?
When you spend all your time together, you end up saturating or "asphyxiating" your relationship.
It's perfectly normal and healthy to spend time apart.
He is giving you a clear sign that this is what he needs. You have no choice but to respect it.
If you were spending every single minute together, you would end up being very dependent towards each other, which is not good on the long term.
Be comfortable with spending time without him.
Focus on your friends, career or studies.
You'll notice that when you meet again, this enhances the moments you spend together.
It is like breathing in and breathing out. It is natural and healthy.