The dark room idea is not recommended any more by the experts. Even those that that do, only recommend it for a few days.

It sounds like your extended dark room environment may have set you up to be very sensitive to outside environment. Sunglasses and wide brimmed hats work well in bright sun. Foam ear plugs help when there is too much sound stimulation. First, just try an ear plug in your left ear. This works many. If the sounds are still too hard to tolerate, use ear plugs in both ears.

Mack's brand are good ear plus and widely available.

Anxiety about another head impact actually makes you more likely to suffer another as anxiety increases lack of coordination problems. Go out when crowds are light. Try to avoid areas with too much visual and auditory stimulation. Stay away from the ice and such risky environments and you will be fine. Be real. How often have you tripped and fallen in your life (off the ice)? Trips and falls are rare.

It will really help if you try to get on with your life by reducing the risky activities and enjoying the non-risk activities. No booze and places where drunk people are.

Give yourself time to get back into your life and you will be fine.

Have you tried any neck therapy ? Many headaches are caused by subtle upper neck injuries. The neck will not usually be symptomatic but muscle spasms from the neck can cause headaches. Excessive bed rest can put a strain on the neck as one tosses and turns.