Part time but feels like the worst job ever

I recently switched out of a full-time director job to a part-time writing job because of family responsibilities and needing some breathing room. Well the part-time job is hell on earth. It's like the most intense gig ever. PLUS right off the jump I've been invited to a retreat where we have to cook and clean together. 3 days and 3 nights. Which is like double my hours for the week. Then, they surprise me with international travel. Has anyone found part-time gigs to be hell? How do I quit? Like can I quit like right now?