Projectiles with potion effect when hit an entity

Ok so i know that this have been asked before but nothing helped me, so i have this problem where i have a tazer and i wanted to make it so when the projectile hits an entity or a player the projectile give Potion effects, and i did it, the problem is that when i shoot i also recive the potion effects and i dont know why

This is the procedure:

https://imgur.com/a/Nxc1OXr

im from spain, sorry if something is bad spelled