From Longman Dictionary of Contemporary Englishwallow in self-pity/despair/defeat etcwallow in self-pity/despair/defeat etcSAD/UNHAPPYto seem to enjoy being sad etc, especially because you get sympathy from other people – used to show disapproval He’d been feeling sorry for himself, wallowing in self-pity. → wallow
Examples from the Corpus
wallow in self-pity/despair/defeat etc• Look at the criticism for any opportunity to learn from it and to change, without wallowing in self-pity.• What hope can they have, if they see you slumping about like a filleted herring, wallowing in self-pity?• Ego takes great pleasure in wallowing in self-pity, and defending itself against all charges, whatever the cost to others. 