Diodes question is this correct?
There is problem in your calculations:


  -20+ 0.7+0.7 +I2*5.6=0


Should be:


  -20+ 0.7+0.7 +I2*5600=0


Same with 3,3kOhm resistor - you should use this kind of calculation:


  -0.7 +3300*I1=0


Always remember in all of your calculations to use proper unit.