I wasn't aware of that. Welp, Boomers, amirite? j/k
He doesn't need fixing.
Simply ignore all the ridiculous crap and concentrate on writing great Wally West/Flash stories again.
Set him back into Keystone, Linda, kids and go nuts.
He has strong links with the entire DCU. From JLA to Titans to the Rogues. You could write 2 years worth of stories without scratching the surface.
"My name is Wally West. I'm the fastest man alive!"
I'll try being nicer if you try being smarter.
Retire him. He offers nothing to franchise at this point. Speed Metal wrapped up the problems with the character. Now he's ready to bow out from superhero game and settle down with his family.
For what it's worth, what I've heard it's that the plans for 5G involved bringing everyone's stories to a close, followed by either a time skip or just the imposition of the new timeline with age adjustments and the introduction of the 5G replacements. While the “payoff” has largely been scrapped (if 5G happens, it will be presented as an “in the future” event), the lead up that involves wrapping everything up still seems to be in play.
So with that in mind, I won't be surprised if Wally does retire after Death Metal. But if he does, he's unlikely to be alone: expect Barry to retire as well.
Rogue wears rouge.
Angel knows all the angles.
You move on to something else with him.