Armor of Agathys + Arcane Ward from Abjurers is an amazing combination if you wish to be at melee. Great endurance with good retribution damage as Ludic pointed out. And since you are a Wizard, you can still do all the controlling shenanigans. My preferred way to build upon that is through a Mark of Warding Dwarf, but a single level of Hexblade (as always), will do wonders to you.

Another Wizard subclass that is quite good at close-quarters is the Enchanter in order to deploy Hypnotic Gaze. Cast some BA concentrado spell like Flaming Sphere, lockdown one enemy and go after the rest. It’s super effective.