That definitely looks like a Lesser Weever to me. Hope it wan't too painful when you got stung. Apparently people have different reactions to being stung......some hardly feel anything, others go through excruciating pain.
I have never been stung myself, but I would imagine it would all depend on how deep and how much poison was injected through it's spines into the 'victim'.
Nasty little creatures, to deal with the poison immerse the stung appendage -arm/foot etc, in hot water , as hot as you can stand.