Injured and missing workouts

Hello there,

First off I am training for my first Ironman in Cozumel this year and am following the 20 week BT training plan. I am not sure how many workouts I can miss due to injury or illness and still finish the race. My goal is 14 hours and all my training times make me believe I am in the right direction. Now the problem, 3 weeks ago I dropped a heavy item on the top of my foot and continued training and it led to a ligament strain. Did my first run on it yesterday for and hour and it felt great with only a week off. So I think that problem has been resolved. I put in a extra time on the bike to make up for the missed runs. The next problem is that today at work I noticed a insect bite on my left thigh. Knowing how I am with insect bites, it is going to get infected and be a pain in the . I am prone to staph infections. Tomarrow morning I am going to the doctor to get antibiotic and try and nip this in the bud. I don't know if I can train with a staph infections. The area is already red and warm to the touch. My problem is I don't know how many workouts I can miss and still meet my goal. I feel like a real slug when I miss a workout. In the training I am up to 56 mile bikes and 13 mile runs. Bike takes 3 hours, and run takes 2 hrs. The race is only 3 months away at the end of november. I feel great after I get done with those long workouts. If anyone has any insight for me that would be great, I know I am not alone but have no friends that have ever done an IM race.