Couple of questions

For those of you who have read my other thread "first IM- your thoughts", you know that i started a twelve week training ramp up for Beach2Battleship.  The first three weeks went well, with long rides of 80, 90, 100 miles and long runs of 10, 11, 12 miles respectively and average of 12-13 hours per week. 
Friday, Sept. 4th I started to feel ill- body aches, slight fever, headache, etc., so took saturday's scheduled off day and also skipped long ride on sunday.  I rode monday- not long (30 miles) and felt weak, went hard yesterday for a 1.5 hour brick.  Today, I have a terrible headache, feel weak again.  What to do?  I am freaking out, as the IM is 8 weeks away, and I already missed one long ride and feel i am in jeopardy of missing Friday's long run or Sunday's scheduled Century.
Should I just scrap the next couple of days in the hopes of feeling better for friday's run, and what type of fitness am I losing during this sickness?  Help!