Welcome to the forums, petergee!
You have great scores, but in my opinion closing all those TLs and opening a new one is definitely not the way to go if you're looking to increase your scores to 800+. You should have downgraded whatever you could so that you would avoid AFs, and only closed whatever truly couldn't be downgraded and couldn't make sense no matter what you did. Anyway, luckily FICO scores still take closed accounts into consideration for a decade so if you just your new Discover card regularly and PIF while having a low utiliziation, you'll be on track to 800.
Ouch! Agree what's done is done, though, so no use going down that path of discussion. Optimal reporting on your Discover will be $5 to 8.9% of the limit. You will lose a few points for more than 50% of your revolving accounts reporting a balance (in this case 100%) since you do not have 3 or more to balance out, but perhaps not more points than 0 cards reporting a balance. A Share Secured Loan may be a good option that doesn't really cost much at all since you pay most of it off immediately before accruing interest and just drag out really tiny apyments over the course of years to have an open installment loan. That can be good for quite a few points!
