Drink more water. The cramps are coming from the Clenbuterol. I use to hate the clen so much, and no matter what i try to do the cramps would come back. Just make sure to drink more water, it cured it for me.

The Tiredness, may just be your body telling you to take it easy, you may be over training or just run down from all the workouts and working your job. Maybe just take a day off from training, on a day you do not have work and that way your body can just relax all day. See if it helps you out.