The first step of any solution is recognizing the problem. I am glad you figured out you need validation so much and people use this to manipulate you. This is already a great step. Now, maybe start to notice when you are validated and how you feel and keep tabs on that until you learn to differentiate the feeling of real genuine validation vs a feeling for the sake of validation. As you keep tabs on, eventually, I hope it will become automatic and internalized.
This is something I challenged with my therapist. He loves giving validation and I realized I felt shame when he did that because I was validated for all the wrong things as a child so I know what negative validation is and all validations give me the same thing.
I am working on it but I prefer honest empathy to validation to me, validation gives me cheap empathy feeling - obligated to validate me cause there was no empathy to give me.