I wonder why you ask about how to be grateful. Did the Ts or other professionals suggest you need to work on being grateful? Or is it something you learned in your family?
I find that feeling gratitude can be positive and life-enhancing when it's a genuine feeling and genuinely applied to something good. But I'm not sure it is at all helpful when thinking about an abusive situation. That's normally something which was awful and shouldn't have happened, rather than anything to be grateful for. And the idea that you 'should be grateful ' would then just be another layer of things to be upset about.
No sure if it's a helpful reply. I hope you feel better