@Effed I am someone in a fairly similar scenario (albeit my "trigger" was not as traumatic as yours but our current situation seem very similar). I totally recognise your desire to pick up your old life/your previous "cognitive" abilities/physical abilities so quickly. I'm a few years on from it and I really understand what you're saying. It's so hard. Would I be right in saying your posts (especially your OP) took you quite a while and effort to word and put together? They are obviously completely articulate so please don't think I'm saying that they aren't! I'm saying I can recognise for myself the work you've put in and how you've taken the time and perhaps it's frustrated you a little that it's been so hard even just to do this thread? I will try and find any similar threads I started a few years back as they may be comforting for you.
Anyway. With the benefit of hindsight, this is what I would go back and say to myself 18 months in, so I hope you don't take it the wrong way 
You are only 18 months on, that is such a little time, especially for the "rehab" you've had to have. Stop trying to run and pick up the threads so quickly. (If I was actually talking to myself I'd say calm the fuck down 
)
It's very very very hard to come to terms with such a life changing situation with such long lasting serious effects. My neurologist said see it as though you have had a previous life of many years (eg I had over 35 years of good health behind me!) but now you have to completely change direction, you can't do it immediately. it's like steering a really big heavy lorry ( obviously he explained it a lot better but ironically I can't remember the exact wording!) It's not as though you've just braked immediately to a stop and can just instantly get back to driving at 60mph. You've got a load of gear changes ahead and you just have to accept it's not 0-60 in 3 seconds.
That rang such a bell with me. I was so anxious to return to my old life exactly as it was and it took me a long time to realise I couldn't just do that. I'm an impatient hurrying type of person at the best of times and it felt like I was being forced to be passive and sit quietly when I just wanted to run (preferably as fast and as far away from what had just happened to me) So fucking FRUSTRATING.
All these suggestions of different jobs are really helpful (some really good ideas) but perhaps your best "investment" right at the moment would be to take more time to work things out and get a bit of distance. I know it's easy to say that but not easy to do yourself, if there are immediate financial worries! and I do roll my eyes myself at people saying "nothing is worth the cost of your life" when you have bills to pay, but there is some truth in it. If you were still in hospital you'd have no choice, just because you're home doesn't mean you're ready to do as much as you really want to.
Who is supporting you medical wise - neurology? They should be able to give you useful contacts/links, Headway is a good one and actually epilepsy societies/forums may be useful especially for the "blacking out" periods (are they seizures? Absence/focal perhaps not tonic clinic?) Even if they aren't classed in exactly that term, the effects are very similar so there are a lot of practical solutions which have helped me hugely eg don't use a kettle, use a one cup dispenser thing, have useful information on your phone Home Screen for any disorientation eg telephone numbers, or a smart watch with alert facility...there's loads. Just stuff like that made me feel like I was doing something to help myself. Your local council should also be able to do a care needs assessment and advise on any adaptations, that's a whole subject worthy of another thread! As is your family life, DH and DCs. They sound supportive which is so good but I know how extensive the ripples are for something like this.
Anyway, at the risk of sounding like Ferris fucking Bueller
perhaps it's a good time to slow down a bit, rather than trying to get new career/job right now, put that time into yourself, the internal investment not external (if that makes any sense?) your job/career search will actually be more successful if you take this time now to speak to your medical team (and whoever they recommend and the support mentioned in this thread) and be realistic about what you can't do - this is easier if you think of it as what I can't do at the moment. (Yeah, at the moment, just stop working without taking breaks, you'll fuck yourself up, sort of advice
. Short shifts are more doable and make you'll feel you're succeeding getting through four hours than fucking up eight hours if that makes sense. But you need to spend time patiently working all this out with your medical team and the right third party support. It's shit, I know!
I'm not very articulate myself these days, this has taken me over an hour to type! and I'm sure it's a bit waffly but I just wanted to let you know you are not alone, people do understand and know what it feels like and it will get easier. I promise. Please do feel free to PM me if you want to.