I'm glad you've had help from a psychologist @Till23 . I hope you'll be able to continue with them even if it's less frequent.
I only started trying to deal with my cptsd about a year ago although in retrospect it damaged me from early times. I was ineligible for longterm help with the first psychologist and the second one was quite unsuitable. I've given up on therapy fir now but hope to get some guidance on current problems from a MH social worker.
I'm sorry you're struggling with self-worth post retirement. Perhaps you'll have a chance to pursue hobbies or interests now you have more time, or find a volunteering opportunity. I've been limited by depression and lack of transport (I don't drive).
I trust you're feeling less stressed now. I also retired early because I wasn't coping and hadn't made financial plans but things worked out OK.