How will the VA handle a supplemental claim to have a mistaken disability that I was awarded removed from my file?

I am currently filing a supplemental claim to get rid of a disability (Adjustment Disorder) I was awarded in 2016. I rescinded the benefits a few years ago and was reevaluated and had it removed to 0%. However, it was never something I actually struggled with and I am wanting to get it whipped from my record all together. A VA rep suggested I do a supplemental claim and claim that there was a mistake.

I have all of the money set aside in a savings account that they paid me and I am ready to pay it back.

So my question is, what will this look like? Will they reevaluate me? How can they prove or disprove that I should or should not have been diagnosed in the first place? I am wanting to go back in after I graduate with my Masters degree and am hoping to get all of this taken care of before I process.