Just tell him honestly. It sounds like you know what you want.
How do I tell my BF that I don't want to come over every single week(end)? It's cutting into my personal/cool down time. It's causing a rift between my family and I because I'm not home. I have strong feelings for him, but I feel a little smothered.
On the occassion that you want to do something else, like spend time with your family .. Say the words "I'm not coming over, I'm spending the time with my family" .. Or even invite him to a family event .. Whichever works for you.
FROM OP
I called as I usually do today, and he tried to pressure me to come over to his place tomorrow. I said that I was busy tomorrow, and inquired if he wanted to maybe come over to my house, but he said no. I told him that I wanted to be home for a while, and even though his response was a little bitter, I believe he got the point because he stopped bugging me about it.
This is something that I'll need to work on with him I think, but thank you all for the advice!
Tell him that you enjoy spending time with him, but just like everything in life, too much of a good thing isn't good at all. Just kidding. That's probably not the way to approach a person. Let him know that you enjoy spending time with him, but you can't spend every spare moment you have with him because you need time to yourself and time to spend with your family.