Memory Loss?

So basically I have my mocks next week and I can’t remember anything at all. I have been revising but I always end up forgetting everything. I try my very best to do effective revision and try different things but nothing seems to be working. Like no matter what I do I forget everything. It’s really disheartening as when I have exams I have to physically force myself to remember and even then I can’t remember much. Due to this I have been getting bad grades for my exams and I need to prove to my teachers that I could do it. Because if I get bad grades for my mocks I feel like they are going to think that I’m not trying. But it’s not only for education: for example, when I’m talking to someone I end up talking about the same thing again as I forget that we’ve talked about it just 5 mins ago etc. I don’t know what to do. It may sound like I’m exaggerating things but I’m not. And it’s not stress that’s causing this. Has anyone got any tips for my mocks and my memory 😕