Diagnosed with Medulloblastoma at 19

I was diagnosed with Medulloblastoma when I was 19. I'm 20 now and had the tumor removed through surgery a little over a year ago. I have undergone 6 weeks of daily proton therapy and 4 rounds of chemotherapy since then and have recently finished my last round of chemo for the time being. I have had regular MRI scans since beginning chemo therapy and thankfully haven't had any signs of tumor growth or spread since my surgery. Yet I still have major anxiety and feel an impending sense of doom every time I reflect. What are my chances of long term survival at this point and how should I cope?