It sounds like a 700c x 37 or 38mm tire would be good for your next pair. The Panaracer "Gravelking SS Plus" or "Graveling Plus" would be good for what you've described. The "durable" versions of Teravail Rampart and Washburn are a bit sturdier. Schwalbe Marathon (E-Plus, Plus Tour, Mondial, or Almotion) tires are very tough and durable tires that are well suited to heavy loads.