That "Robin Williams and Depression as a Muse" blog really is an amazing peek into so much of Pat's psyche. The way he frames his breakup, they were a perfectly happy couple with zero problems whatsoever. Then one day, out of the blue, she drops an atomic bomb: I'm pregnant, I'm leaving you, I never loved you, I was never attracted to you, I never respected you, etc.
Patrick then makes sure to stress that his ex-wife lied when she said all of this. She still lies, to this day. The truth is she did love him, she was attracted to him, and she absolutely respected him. Anyone mentally healthy, who has been in previous romantic relationships, can cope with the reality of what happened at the end, even if you got your heart broken. Or cheated on, or your partner wasn't that into you when the puppy love stage ended.
But Patrick has been dumped once in his life, and it's such a goddamn tragedy that he's threatened to kill his ex, and to this day refers to her as a "traitor". All while she's raising his child and he's paying $0 in child support.
Normal people can look back on a past relationship and hopefully have some "I did this wrong, they did that wrong", Patrick needs to be the superhero who had his daughter stolen by the cruel traitor supervillain who he wants to murder for the good of humanity.