I think the pity and contempt that the end of the sentence are for the people who are causing (because it can't be himself of course!) his domestic affairs - which as we know from later are very severe at the moment. I think the pity and contempt that he is able to feel after reading his favorite volumn are for the people who are hounding him for the cash he owes them. He has to turn it to pity and contempt otherwise he might be implicated in the mess that surrounds him.