Im playing through halflife 1 right now and i just got to the alien world part with that 4 legged spider. Im at the part where im in this pit with like a webbing over it, im in the pit and the thing is looking down at me. Ive shot ALL my ammo into its sack thing and only have 5 c4 things left (i saved before i jumped in and still had my ammo). The damn thing isnt dead and it aint coming down. What do i do?