Wuqūfan is a verbal noun used here in an accusative circumstantial sense, conveying something close to wāqifīn, “while my companions stood waiting.” This is a verbal noun expressing a state.
In lā tahluk, lā is prohibitive and tahluk is a second-person singular imperfect in the jussive: “do not ruin yourself.” Asan indicates grief and its emotional force.
Wa-tajammal is an imperative from Form V, calling for patience, restraint, and dignity. Prohibition and command work together: avoid destructive grief and adopt a composed response.