I broke a quest and don't know how to fix it

I was playing the quest "Elemental Exercise" and while in the cave portion of the quest, I went up a waterfall looking for the exit once the cave collapsed. I swam up the waterfall only to get stuck at the top because I had swam underneath the barrier blocks at the top. You aren't supposed to get up there, but I did being in swim mode. I was stuck on the opposite side of the barriers and didn't know what to do, so I did /kill to get out. The section in the collapsed cave is off the main map so I can't get back to it to complete the quest. Can I get help from admins or is there a way I can reset it or something?

 

tried go back to the cave?

 

I don't know where it is and can't track it because the compass points off the edge of the map when I track the quest

 

check wiki, go to the cave that you originally went in

 

Ok I found the coords I’ll try it

 

It worked thanks