Have I made a mistake?

So I’ve just realised I may have made a mistake. And this is the issue. All of uni and now it’s just clicked. At my previous uni I basically got in via clearing.

I had CUU as my grades took a gap year then went and did the 1 U grade and left the other and took a new subject. But all this one I haven’t been including it on my apps. I’m a little concerned I’ve graduated and even got on my course now and I didn’t think I had to disclose as I literally got 1 mark for both papers. Don’t ask why I had a serious thing happen in my life. I’ve only ever disclosed that I have CCC


What should I do...