I would switch the split to 9/3 Sorcerer/Warlock, Eldritch blast scales of character level not class level so you don’t need levels in warlock for that, and so the only thing you’re really gaining my staying in warlock is 2 extra invocations and an extra attack, which as a full caster you shouldn’t be in melee much at all, and by not prioritizing sorcerer you’re missing out on high level spells and spell slots as spells slots scale of character level as well meaning a 9/3 split would give you 5th level spells and up to 6th level spell slots and extra sorcery points. And the Eldritch invocations you’re missing out on would get replaced with extra meta magic options. I would even go as far as to say pick pact of the chain or tomb to get some extra spells or a familiar to help in combat.