How do I find a balance between schoolwork, boyfriend and part time job ?

I'm currently doing the HSC (final year off school) and things are really getting hard I just have so much on and I really need to focus on school work. But I have a boyfriend and I'm finding it so hard to find time to hang out with him. He is quite persistant too and I feel like i'm always having to make excuses not too see him - which i honestly really want to but I just have so much on all the time. His band is playing tomorow night and I know I should go but I have 2 exams the next day and I really don't have the time. I feel so slack but I know if i go i will do horribly in these tests. ahhhh i just dont know :(