My sister is dx'd, my other sister is not. My dad has insomnia and both parents had mood "issues". So I didn't know I was really different until living in the dorms and kept getting in trouble for "normal" things like rearranging the furniture, jumping on the bed, and sleeping around to much. I was almost kicked out twice in the same semester. Hell same week I think. I wasn't willing to get help until 22. Your kids are lucky it was caught early in life. I couldn't imagine raising kids like myself or my sisters. It was an emergency all the time. I OD 1x, was a regular cutter as a kid, partier but kept my self destructive tendencies to myself. My sisters had/have regular outbursts of violence.

I'm raising a kid with SN anyway I can help just ask. As for genetics it's a crab shoot really but I would investigate if anything may be wrong with either parent (any mood disorder) because what you think is normal may be off. I'd get an individual therapist for yourself because you need the extra support. You may want to get each of your kids a therapist if they don't have one because it's tough on them too.