Hi Blue,
Welcome! I have also taken numerous hits to the head. The life changing one being in feb of 2006. I also suffer from extreme migraine headaches. I would try the prednisone if it is only for a short period of time. This medication is a powerful steroid that is hard on your liver and can cause major bloating, water/fluid retention. I have heard it is very helpful for those that can tolerate it. I would not use this as a long term remedy. It may reduce inflammation enough to relieve the problem for quite a while. I have found meditation to be the number one most helpful thing and it is all natural with no side effects. Meditation helps with all the symptoms especially the anxiety and insomnia. Try it out while you are in bed trying to go to sleep. Just try concentrating on your breathing. Also sunglasses for light sensitivity, earplugs for noise sensitivity and eating a well balanced diet are crucial. You can find a wide variety of guided meditations or just relaxing meditation music on u-tube. I have found that nature sounds like water or whales singing help for relaxation and meditation. These can also be used as "white noise" to block out unwanted noise. Above all you need to REST. Give yourself and your brain a break. Keep out of crowded, noisy environments. You can and will recover. Some do not recover to what their past life was but find a new way of living that can be equal to or greater than the level you were at prior to your injuries. You just have to adapt and learn new ways to live and enjoy life. Listen to your body. These headaches are telling you that you are doing too much and need to change things. Good to have you here with us. Don't give up. Things get better. This is a slow recovery.
Brain