Why do I feel scared of the future with my fiance?

Ok so I’ve been dating my boyfriend (now my fiance) for 3 years now. We met in high school in the 11th grade ands its been great! So heres the hard part. Hes white and im biracial. My mom is white and dad is black. I love both of my”sides” and is very proud of it. Since we’ve been together we came across people who werent really in to the dating of different races…even people who we thought were our friends. Growing up mixed was not easy at all because of these peoples ideas. We are very much in love with each other and dont really pay attention to the stares or comments. But now since we are getting married in sept and the kids subject is on our minds I get this pit in my stomach. I want kids dont get me wrong but im worried about what he or she will go thru, and if im strong enough to not kill someone if he or she comes home from school one day crying because of something said…I’ve explained this to my fiance but he doesnt get what im worried about. Probably because he was not in my shoes as a kid. Id like to here from parents of mixed children and there experiences and I wanna know if im worrying to much or do you think that its a good reason to be torn about it.