I've followed all the advice for after a break up, but I still can't cope. What now?

My boyfriend broke up with me and I’ve done all the right things- I’ve cut off all contact in order to get over him, my friends are really supportive and I have already filled my weekend with plans with them, and I can be easily distracted by them at school. But at home on week nights, when I’ve run out of homework to do, or when I’m lying in bed trying to get to sleep, I can’t help but think about how much I miss him. I become incapacitated with the pain and have trouble breathing. So now what? What can I do to help me sleep at night? What else can I do to get over him?