This is heartbreaking. I'm sorry life has been so unfair to you.
Your wants are reasonable. Your difficulty trusting is earned. Can you really call it paranoia if you've been genuinely wronged when trusting before?
Self-hatred, given all of this, is definitely your ego trying to protect you in some way. It sucks because it's like allergies where your body (mind) is attacking itself in a panic.
I had someone ask me recently why self-hatred happens. My answer was something like this:
When faced with repeated bad outcomes, the ego might conclude the safest action going forward is to pre-emptively kill any hope to avoid the situation where the bad outcome might occur. You mentioned putting up walls, which is pretty spot-on if you've ever listened to "The Wall" by Pink Floyd: repeated trauma/abuse in childhood leads the main character to hide himself from everyone behind a mental wall.
Typically, when we fail, having a "good attitude" and pressing on and trying to improve things is the reaction we're supposed to have. But, eventually, everyone can be worn down, and there's no energy left for that good attitude reaction, and trying it will lead to full collapse, so we really need to rest first. But hope is our built-in natural reaction, so the ego has to say really mean things to us to get us to give up that hope.
For instance, you are not an "object to be used," because no one is. Even the worst people on the planet shouldn't be dehumanized in that way. Using someone else like an object is evil.
Back to paranoia v. caution: when you're in a critical state of danger, you're going to be more cautious, right? HP is low, there's frantic beeping and alarm bells: the natural instinct is to throw out all offense and focus on defense. It's healthy to identify that you're in that state of extreme caution and know that it isn't always the proper strategy, but right now, you need rest.
You deserve rest. You deserve to feel safe. It's far easier said than done but I think you need to try letting yourself rest. Now is not the time to search for love and acceptance. Now is not the time to accomplish things to make people want you. Now is the time for rest and self-care.
You might genuinely hate yourself, but you still are the one who has to care for yourself - you can think of it like taking care of a houseplant if you want to depersonalize it. That's another problem with the self-hatred that the ego doesn't anticipate: self-hatred leads to not taking care of the self which creates a circular void of feeling worse and worse.
It can always get worse. That's one of the saddest truths of this existence. But, because of that, even if you hate yourself, you should take care of yourself to reduce the misery, or at least stop the bleeding.
I really hope things can get a little less bad.
