Hey Mike,
I'm on the same everyman (3hr core with 3 20 min naps). For me the
worst adjustment time was about days 6-9.
So where you are at, I believe is the worst part. You are right where
most people quit.
Stay active for those first 90 minutes after your core especially. You
are changing a sleep schedule that you have spent your whole life
adjusting to.
Go out for a walk, watch an action movie or anything else you're
interested in.
When I got to day 10 I felt I was about 90% adjusted. I wake at 2 AM
and am perfectly able to sit and read, study, etc.
But you must hang in there, and you cannot cheat, even a little.
About day 30 you will be fully adjusted and you will never want to go
back to monophasic. (At least I don't).
Good luck
Joe