I am very sorry to hear about your 'relapse.' I think it is easy to get caught up in the negatives here. But your story is filled with positives. First of all, you had 2 weeks of being headache-free. That is a huge step. The fact that you were able to do light cardio also is a great sign. You just pushed yourself a bit too much too soon. I suppose it is hard to know where to draw the line, so being overly cautious is a good option. I have had headaches nonstop for nearly 7 months, so I haven't had an opportunity to exercise. But, if I were you, I'd assume I wasn't healed for several more months. When you feel better, do very light conditioning, increasing the intensity by only minuscule amounts over a consistent period. You are much more likely to be able to tolerate the exercise this way. If you feel any symptoms with increased activity, then simply lessen the intensity.

I would not lose hope. Your story is positive. You had a setback, and now will have some more recovery time ahead. But you have not totally regressed. It is doubtful you did any more damage to your brain. Stay positive and you will get better.