Better to burn out than to fade away

I am saddled with a severe case of burn out at work. It's been a tough year for me.. A couple of very high end multi million $$ projects on Beacon Street for very wealthy and demanding people combined with very difficult architects and designers, has really taken it's toll. Being a punching bag for general contractors is not a satisfying occupation. I spent two weeks overseas "on vacation" this past May, tending to my father. Not exactly a vacation. That event took more out of me than I can even comprehend.. My coach was astonished that I had any good form at all this year, after what happened (losing my dad) The rest of my vacation time wasn't used for laying on a sandy beach or anything either. I went swimming all of twice, all year- at Narragansett Town Beach no less..
Long story short, I plan to take the day after Christmas off and the day after New Year's Day off. That means that after this weekend, it's 3 days work, 4 days rest, 3 days work, 4 days rest. Niiii-ice. But in order for this to happen without having a meltdown at work, I'm putting in a lot of extra time both last week and this week. Probably 70+ hours. It's little wonder that my heart rate's elevated..
How many hours/miles of base fitness can I add to the hopper for 2009? As it stands now, I will easily pass 8000 total miles for 2008 with just a few more three hour rides.