Like the disclaimers say we can't diagnose, but your post doesn't sound delusional or out of touch with reality. And lots of people philosophize or ramble without having any issues. But your right that feelings sometimes just don't go away, even when we think they aren't very rational.

Is it correct to assume you are, or have been, in therapy? That would seem like a good place to talk about these feelings and hopefully figure out what's causing them.

You also mention having been diagnosed before. So maybe you could also go back for another evaluation?

It sounds like the GAD talking, but I don't have any personal experience with that. So maybe someone else here can offer some more experienced support.

Hang in there. If you've mostly recovered from depression and panic disorder, you're a very strong and capable person. You can deal with this.