If I use Hex (PHB p251) on a creature and next turn I use, say Eldritch Blast as my action and Spiritual Weapon (PHB p278) as my bonus, would Spiritual Weapon also get hex's extra damage? I'm a bit confused by the wording of what's 'me' and what's 'mine'.
Until the spell ends, you deal an extra 1d6 necrotic damage to the target whenever you hit it with an attack.
From spiritual weapon:
When you cast the spell, you can make a melee spell attack against a creature within 5 feet of the weapon.
You are considered to be making the attack when you attack with spiritual weapon; you deal an extra 1d6 damage when you hit a target with an attack. Therefore, you deal that extra damage when you hit your target, whether with eldritch blast or spiritual weapon.