Does the 2 hours of activity 30 minutes of rest formula sound like a good one? Or should I be more conservative at first?

I've felt worse the past few days than I have since the concussion, certainly worse in terms of variety of headaches, and I feel I'm less able to concentrate, and the ringing in the ears is a totally new symptom. Is it possible to have setbacks worse than the initial injury? Or could this be a cumulative effect of head bumps, my last one being the straw that broke the camels back? Or side effects of the amitriptyline? Or just the stress from travel and an emotional week last week?

I've been keeping my anxiety somewhat reined in (I think because I'm just exhausted from worrying). I'm sure it's an interplay of all of these, and I'm starting to be OK with not knowing, but part of me still really wants to know why!