Welcome, ghost bird!
I can relate to so much of what you said.
I agree with what wanderingstream said about building yourself up in your own eyes. It does help. I've always struggled with affirmations. But I figured out a weird trick around it. I have a teddy bear (yup, grown*** legit adult). It is somehow easier for me to receive positive messages when it... kind of goes through a "second party". Sounds silly, but it helps me a lot. I've tried to analyze how I do this, and the best explanation I've come up with is that I project warm feelings and reflect them back as if they are coming from him. And have him say nice things when I need it.
If that might help you, great, if not, ignore.
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Makes me sick to the heart, Oh I feel so tired. And the way the rain comes down hard, that's how I feel inside.
--The Cure