Train more one limb at a time. Do different exercices - and by that I mean for a couple of month staying away from your usual, favourite ones.
Have some ART done, foam roller, try posture exercices.
It took you years to get to this not so bad posture. It’ll take months to correct it and in the process of doing so you’ll have fun, change things around and be out of your usual routine. You’ll probably even be stronger when you get back to what you’re doing.
One thing you shouldnt do: doing 90%+ of your routine exactly like you’re doing it right now and expecting different results!