Coping with nightmares

Hi

i have nightmares every day and it’s got to the point where I’m just terrified to sleep. I’ve always had them but they are just getting worse as I get older. However it’s causing me to be really tired all the time and I’m getting angry and annoyed at every little thing and generally I’m a really nice patient person. As well as the stress of school not helping with things . I have exams coming up soon , which my teachers never let me forget . Everything just seems ten times worse when I’m tired . Does anyone have any advice on how to deal with the nightmares ? I just could do with going to sleep whilst not being scared of my own imagination.