Glad to hear your injuries are relatively minor and healing quickly. I'll second the notion that being tired is normal--you're body is working over time.

A while back my husband was in a similar accident that split his helmet. He was working in a bike shop at the time and saved it for display in the shop. They highlighted the crack and whenever somebody (usually teenagers) started in about how goofy they look they'd show them the damage and explain he got a concussion anyway and it saved his skull from splitting. It's hard to argue against helmets with physical evidence like that.