GCSEs stress

I’m going into year eleven and I’m stressing out. I want 6s and 7s to turn into 9s and it’s just not happening. Every night during the summer holidays has made me stressed and worried, to the point where I’ll screw myself over, sleeping at weird times and waking up so late. I can’t focus on revising, and I’m just freaking out. I feel like I’m running out of time, and I won’t be able to achieve what I want, but at the same time I’m such a bad procrastinator. I’m so scared for my GCSEs, everyone keeps saying they're not a big deal but they stress me out so much I don’t know what to do. I barely have a year left, what do i do