Stop telling people you "broke up", they will immediately assume heart break, fights, etc. Just say that you guys are now just best friends and roomates. If they probe further, just say that it was a mutually amicable decission. Using words that don't imply pain, should diffuse their instinct to comfort and confussion when you don't need comfort.
This is the second time today, that I'm glad I live in Southern CA. I ask my kids to describe their friends, usually they can't, so I probe, are they black, asian, hispanic, white, etc. Their answer "I don't know", they're just my friend
. Mixed race is the norm around here.