What others have said is very useful advice, and I don't really need to add to that. But I can add some personal inputs from a milder TBI than many here suffered. You need to buckle down quite a lot and accept the situation you're in, thats hard. For the first timers I think most of us (I know I did) spend the first few weeks just trying to understand wtf was happening, as the doctors sure aren't useful and they seem to think its more a 2 week injury for some reason.

Try and let go of as many 'normal life' things as you can and focus on knowing you'll need to rest, this unfortunately will be a big change hopefully only short term.

In terms of getting better, try and think in weeks not days. For instance, is your headache better than it was 3 weeks ago? Then you're making progress.

The boredom I found was the worse thing and I did things like use the computer, watch tv etc to entertain myself that I probably shouldn't have. There is no real cure for this. Try and rest as much as you can especially in the first month or two.

I do suspect in a few months you'll be feeling a lot better than you do now. I know that sounds like an eternity, but this is a life changing injury, even if only short-medium term. I don't know your relationship situation, but if he isn't supportive and caring i'd remember that and consider if its something you want. I do think after time has passed people will come around to caring, even if initially it just seems like "a hit on the head" to them.