Well mrssmith if you're going to get down to that level of analysis;
I think I crossed the line.
That depends on whether the OP is using "think" in the sense of "consider/believe" ("I think apples are nicer than oranges"), or "think" in the sense of conveying uncertainty. You've read it as the latter, but it could be the former - I don't know.
Now I don't think we swear at each other and I saw red.
I read that as the OP explaining what had triggered her loss of temper. She didn't "see red" at the petty chicken argument, she didn't "see red" when her DH insisted on continuing the argument despite her asking him to "forget it". She "saw red" when he swore. (Doesn't mean her response was justified.)
DH went upstairs and either slammed a door really hard or hit a wall.
Again, a factual description. They were both angry. Doesn't mean she is minimising her actions. Call me naive, but I don't think you write a post like the OP's to minimise your actions. If you want to minimise your actions, you don't post at all.
At no point have I said that the OP's actions were reasonable. But I don't think the level of judginess from some posters on minimal information is reasonable either.