ANSWER - There are a couple of ways of looking at this. The simplest would be that when you injured yourself in getting the concussion you also suffered a small amount of brain damage which prevented your brain from being able to conduct some of the more complex functions it could prior to your injury. It's hard to be too precise as you don't mention specifically what the gifts are but a small amount of damage to the brain could certainly inhibit instinctive and possibly even precognitive gifts.
If the loss of your gifts was caused by brain damage then that is not to say the loss is permanent. Sometimes the brain can recover over time. This (to the best of my knowledge) hasn't been tested with what we might term spiritual gifts but it has been tested with basic functions such as speech. Speech therapists will work with brain damaged patients using oral motor exercises to help them to recover their ability to speak. Basically they are encouraging patients to practise the skills they once had so I'd suggest that might be something worth doing in your case as well. Instead of waiting for your gifts to come back, consciously work with the gifts you once had and see if repeated effort helps your brain to regain them.
The other explanation I could offer is that your mind (not your brain) has gone into overload at the double impact of your injury and your close to death experience and as a result it has gone into a temporary
shock which has reduced the capacity of some of your gifts. This would be quite a natural reaction to what you have gone through and unlikely to be a permanent reaction. Giving yourself time to come to terms with your experience and gradually practising with your gifts (as discussed) above should gently coax your brain back toward the abilities you used to have.