Strength training/Fat loss...

I've decided I'm going to concentrate on weight loss first. Probably just for about a month. However, I've been doing strenght training then alot of cardio. Now I understand I wont really get any bigger because the calories/protein are being used by the cardio. So that leaves two questions...

1. I dont want to lose what muscles I have and strength training + the cardio has gotten them bigger and harder, but should I just not bother? Or maybe do a circuit routine to try to keep my heart rate up?

2. If I do both then take a lower calorie protein supplement would that do anything to help?

Generally, you'll start to lose muscle if you do extremely long cardio (look at marathoners, lungs with a pair of legs).

To maintain muscle mass, keep your cardio shorter, 20-30 minutes, and intense.