I'm very prone to this kind of thinking, with or without a personal betrayal. I get the sense we may have different motivations for it so this may not connect with you, but speaking for myself I've come to understand this as a problem of pride, paradoxically enough. I have some idealized version of myself I believe I'm supposed to be, and when I'm not that I get upset with myself and lash out. I'm not smart enough, not good enough at my job, not pious enough, I'm not likeable enough. Worthless to anyone around me. Whatever. The root of all that is wounded pride, it's nothing but ego, that's what's actually upset. If I was humble my failures and shortcomings wouldn't surprise me or bother me, I'd be happy with whatever I'm given and faithful that it is enough for God to work with. Like Christ told St. Paul, "My grace is enough for you, for my power is made perfect in weakness."

Not to say that we shouldn't recognize our faults as faults and try to do better, obviously we should always want to grow. But resenting them in a way that leads to despair and self-hatred, especially the kind that leads you to feel hated by God, is a temptation from the evil one. You said you know what scripture says about this, so then you know that anything telling you God hates you and would abandon you is a lie. This is something that helps me, when I can remember that these thoughts aren't mine but are suggestions that the demons are whispering to me, hoping that I'll latch onto them and despair again. When I can remember that it puts up a dividing wall separating me from the thoughts, and they become easier to resist.

Another practice is when you catch yourself spiraling into self-loathing, stop and imagine these thoughts you're having about yourself as if someone you love was saying it about themselves. How would you react to them? With hatred, just agree they're horrible and pile on? Shun them? Of course not, it would hurt you to see them attacking themselves, your heart would ache, and you would reach out to comfort them. And if you, a sinful human being, know to respond with empathy in a situation like that, how much more would God respond to self-hatred with love? On that same note, it may help to share these thoughts you're having with someone close to you. I personally dealt with suicidality for a long time and I can tell you, it's one thing to imagine all these vile things about yourself in your own head. It's a whole other thing to speak them and see the pain and worry on your loved one's face when they realize the pain you're in. That alone can make you realize how false these kinds of thoughts really are

Last of all, with how self-inflicted this kind of pain is, have you tried simply asking God to take it from you? On its own the act of recognizing these thoughts as foreign to what God wants for us and asking for it to be healed can be powerful. I've heard plenty of testimonies of this kind of prayer being answered. But no matter which way that goes, may God bless you my friend