Having a hard time understanding breakup

My boyfriend of 7 years and I broke up yesterday.
He told me last week (after he had ignored me for a week before that) that he was in a funk, he didn't know why and that I didn't do anything to cause it. He continued to talk normally as if nothing was wrong to our mutual friends who would tell me that they had talked to him about a hobby or videogame.

I gave him a few days of space before I finally told him that he needed to tell me whether or not he wanted to stay in the relationship because I was tired. Note: I wasn't intending on being "over-dramatic" or whatever, this just isn't the first time that he's gone into a funk for no reason. He didn't respond for a while so I broke up with him. Still not a word.

Granted, for being a teenage relationship, we were extremely serious (especially him) about each other and intended on getting marriage when we both finished college.
We have broken up before but we had always talked about the breakup/why/etc.
He was/is my best friend and I was his. We talked about everything together and now it's just nothing. I'm okay with the breakup but I'm not okay with losing my best-friend.

What's the appropriate time to contact him again? Two weeks? A month? Or just not at all? I have to see him in May for our Senior Graduation but other than that we won't really have any opportunities to see each other. I would like to find out what went wrong on his side and what I did wrong at some point.

What, exactly, was the reason you broke up with him? Because he couldn't articulate how he was feeling, or was there a deeper issue between you two? Sometimes, relationships reach their breaking point, or they just crumble and fall apart. As you get older, you will realize this happens more often than not. I wouldn't recommend trying to be friends, at least not right away. You both need to allow for some healing time, and to mourn the relationship, and that is best done separately. Try focusing on things you enjoy: your friends, family, hobbies, etc. Focus your energy on positive things that bring you joy, and let him do the same. Over time, you won't question everything as much. You probably won't get all the answers you are looking for, but you will eventually find peace within yourself, and you will be able to move on.

I'll make this simple.
If we're talking 7 years. That means you were his 1st, second gf? Given the time, i think he wants to see whats out there like the cool kids and such. Its a wild yet common guess. You're not at fault, leave him be. Find another calf madam.