we were missing; we lackedUsed with a noun in the genitive case to say that something or someone was absent or insufficient for us. In the expression «Только этого нам не хватало!» it means “just what we needed!” or “the last thing we needed!”, usually sarcastically.
RU: Нам не хватало времени, чтобы закончить проект.
EN: We didn’t have enough time to finish the project.