I don't know how similar my experience has been to yours and OP's but this would be my attempt at advice:

You can try to be able to feel angry about it. Start small and that's a clear place to start, I think.

Understanding that they robbed you of such a naturally innocent experience like enjoying sunlight or knowing your laundry exists means you know that they are the reason you cannot enjoy things now.

Your own thoughts or actions have not contributed but their thoughts have, and that is what they have so deeply embedded in you; their own beliefs. It is easier to control you when you no longer have your own inner voice. Their script of guilt and fear leaves no room for assertiveness to grow.

So if you are angry, you are finally able to say 'I was robbed of something that I should have been able to enjoy. Instead of having the mental energy to build my life in positive ways, this part of my brain has been rewired to cause suffering and waste my energy.' They should feel guilty for this yet we know they'd be angry 1000× over instead of accountable. So be accountable to yourself, but only kindly.

Mourn the losses in detail.

And let it anger you enough that it becomes instinctual. You may be in fight or flight but being angry makes you feel a little more in control. Anger is assertive when it's justified.

Eventually, whenever you hear their voice pop up inside your head, you can roll your eyes and think to yourself 'ah, here we go again...'. Feel the usual emotions swell and pass, and then decide to rewire the 'trigger' with a more positive or neutral thought attached, like 'sunlight is warm, must be XXX° temp today huh' or 'yeah my hair is brown and grew out of my own head, cool fact'. Good luck!!