I feel it is sinful to complain about my husband to others. May I speak up about this injustice?

Exposing injustice in order to get help and justice is not forbidden backbiting; it is the right of the one who is wronged. Allah says: “Allah does not like the bad words spoken openly, except by those who are oppressed” (Surah an-Nisa' 4:148). So complaining to those who can help, such as a counsellor, trusted family, a religious officer or the police, is permitted. If you are in danger, call the police on 999, and Talian Kasih 15999 for support. Choose people who can truly help, not those who will merely spread the story. Staying silent is not a sign of patience when it lets injustice continue. See counselling.