I am trying to make a custom item called a "Medigun" in Minecraft. Simply put, when you hold a skull with the name "Medigun", it activates a /execute command. I am trying to make it so that when you hold it, it gives an effect of Regeneration III to every entity around it within 4 blocks. So far, I have the command
/execute @a ~ ~ ~ /effect @e[r=4] minecraft:regeneration 10 2
set up, but when I hold it, all players on the server get Regeneration III. How can I make it so that only players near me will get this effect?