How do you deal with “flooding” during intimacy with your wife or partner. This disorder is absolutely horrible it’s hard to even relax in my own home.

Im interpreting “flooding” as meaning a flood of emotions? Particularly negative/anxiety provoking ones? Look into the practice of Tantric sex. Idea behind that is to use physical intimacy as sort of a form of mindfulness practice where you simply focus on bodily sensations without judging them and without really having a “goal,” just being with whatever surfaces. That may help. There are lots of books about it. Find one with good reviews.