Making sense of Patrick Melrose - pitiable and full of self-pity

Trying to make sense of the character Patrick Melrose, or more specifically of Edward St. Aubyn's depiction of Patrick in volume five of his series, At Last, which takes place, it seems (more than half-way through) entirely at the funeral service for his mother. After an extremely painful section of the novel in which we learn more devastating details about the abuse Patrick suffered at the hands of his sadistic and predatory father, and we are reminded of his mother's self-absorption, indifference, and failure to protect her son, material that can almost make me like Patrick despite his many flaws, St. Aubyn then shows us Patrick the whiner, the soul of self-pity: He goes off on a long revery about the property in France and how much he misses the glorious days of his youth (really? It would seem to me that his childhood home, scene of repeated sexual abuse, would be a terror for him that he would be glad to be rid of) and continues in his bitterness toward his mother for giving the property away to a spiritualist charlatan. Then, he is summoned to NYC to deal with a so-called small trust left by a great-grandparent - he's in NYC when he learns of his mother's death, conveniently putting the entire burden of managing the funeral on the shoulders of beleaguered (ex?) wife, Mary - and he learns the trust amounts to $2.3 million - no matter what this guy does to ruin his life, he always lands on his feet, so to speak. He does make some wise observations - summarizing St. Aubyn's theme - about the wasted lives of those in his social class, people who almost universally (his friend John may be the exception) contribute nothing to society and yet belief they are entitled to the great wealth and privilege that accrue to their social class. At last the funeral service starts, beginning with the Gershwin son, Plenty of Nothing, done in mock black dialect no less! - which Melrose considers perfect for the occasion but I would consider appalling - more self-pity and crude irony. Then one of the spiritualists speaks, an easy target of course for Melrose's scorn - but does he have anything to say? Is there anything he can contribute? If he so loathed his mother - fine, she deserves it, but why pretend otherwise? And if he does have feelings of love and gratitude, why not express them instead of sitting to the sidelines with a perpetual sneer?