The busier you are the less you'll think about your situation. Distraction is a tool we all use here one time or another.
In the meantime google these threads and read the first post of each.
Beyondblue topic the best praise you'll ever get
Beyondblue topic distraction and variety
Welcome to the forums. I'm sorry to hear about the break up. I understand you are feeling really unmotivated and in a lot of grief. I also broke up with my partner of about 3 years in May and had very similar feelings.
As TonyWK mentioned, distractions can be helpful. For me, the most helpful thing is to involve other people in the things I need to do - whether that is simply by telling them what I will do, or by somehow involving them even more. Like if I need to cook dinner, I'll tell them to come over and I'll cook us both dinner. If it's some sort of personal housekeeping, I'll tell them that's all I'm doing today and let them know how it goes tomorrow.
Otherwise, the best suggestion I can offer is to really make sure that you aren't down on yourself for not doing things you planned to do. I understand you want to grieve this next week when you have time, but when it comes to grief, we very rarely have any control over it. So grieve when you feel like you need to, and then get back up when you have a bit of energy.
It's tough. Please keep talking to us if you would like.