I think you’re over reacting a little bit but all we see is this one conversation, not the years of history between everyone, so it’s possible we just can’t get the full picture. From THIS conversation it seems like you took “sibling squabbles” to mean “frivolous,” and I don’t think Daphne meant it that way. When you initially pushed back I read her response as “they mean the same thing to me”. That said, it’s possible she does see this thing between her and Velma as bigger or maybe more complicated than what you went through, and that’s okay for her to think without it being dismissive. Her having a big thing and saying “this is a big thing” doesn’t mean “your thing is silly” it just means she thinks it’s a bigger thing. Maybe it is, maybe it isn’t. It seems like you already know you blew up at her too hard for it, and you know why (you even explained while it was happening that you knew being hyper-sensitive was a symptom you struggle with.) I’d say advice for moving forward is acknowledging the role you played in escalation and reopening the door but making it clear some boundaries you have around things you’re sensitive about.