TITS - time in the saddle.
Somehow you need to carve out a weekend where you can do 5-6 hours of riding on both Sat. and Sunday.
I did 215 miles in 2 days a couple years ago. The first day was a breeze. Getting back on the bike the second day was the hardest thing. It took about an hour to get everything going and for me to feel "normal".
And stay away from convenience store pizza no matter how good it looks at the time. Trust me.