I was and always have been very fortunate that headaches have never been much of a problem for me. When I left the hospital 5 days after my accident, I was given a bottle of an addicting pain med. I never opened it. Even with a broken forearm and jaws, I had only minor pain.
My biggest issues were: My mouth was wired shut. All food & drink through a straw. Having my left arm in a cast made splitting firewood a little difficult.
Exhaustion was a real problem. I only had 6 weeks of part time work to finish up before I retired, I was able to get through 4 hour days.
Mentally, I aged 10 years in less than a second. My ability stay on track was gone. Any distraction and I forget what I was doing. I use Microsoft's To Do List to keep track of everything. It's on my phone, tablet and computer and it synchs. Even if I go to the hardware store to get 2 or 3 things, I need the list. It has been a great help as any improvement in my memory is so slow I can't tell.
I had dizziness at first and have noticed that it reoccurs if I do out of position work. Recently I rebuilt the axle on my boat trailer. That brought it back.
Another issue is that my symptoms are normal for people my age, but not for me.
If I have any advice that is of value, The most important is: KNOW YOUR LIMITATIONS AND LIVE WITHIN THEM!!! You only do more damage or slow down recovery if you don't listen to your body. Take a break when it is tired, feed it when it is hungry. Keep it hydrated. Be patient with yourself, healing takes a lot of time. I've been told many times that I have the patience of a saint, but when I had to be patient with myself It was a whole different story.