My understanding is they fought until they pretty much ran out of ammo and really couldn't fight anymore, they were lacking all other supplies as well, medicines, bandages, food, etc.Well, he was left to die as it is. That he and the Sixth Army fought that long anyway was simply because Stalin had some room in the gulag for them. It took forever to make trying to survive there more appealing than dying in Stalingrad.
Fatboy (Göring) let em down big time.