i lifted weights to attempt to fix postural issues that i noticed in my 20s. it made things worse

the issue was that i lifted weights to make big number go up, instead of using weights as a support tool to explore muscles in the body

Yup, the same happened to me.

The additional strength didn't do anything to fix my posture. It just let me hold my bad posture for even longer, until another muscle would fail.

You need things like Alexander Technique to retrain how you hold and use your body. And things like myofascial release to undo all the new tension you created from all the lifting with bad posture.