Can't complete the Druid quest [Curing the Sick]

[Vanaglore]

I encountered a rare bugged sick gazelle on which I used 2 charges of the item that the NPC gives you and it didn't work. After I killed that gazelle and it respawned afterwards it worked just fine so I'm not sure why would it be bugged on the first place. However, since I used 2 charges, now I cannot complete the quest. The NPC doesn't give any options to get more charges, so I'm unsure about what to do.

If I cancel the quest can I get it again? Should I get a GM to help me?

[Lorilay]

Abandon quest and restart.