I had the same issue. I hate being smothered and my boyfriend wanted to spend time with me 24/7.. that's just what people do nowadays. He was comparing our relationship - how often we saw each other - to other people.
I am busy all the time with work and extracurricular stuff and almost every chance I got I would spend with him. I told him that sometimes I just want to be alone - it's not that I don't want to see him, it's just I need some "me" time!
He still gets angry every once in a while cause we're not together ALL the time, but he understands my needs.
If your boyfriend doesn't understand what you need / want he isn't worth staying with at all!