Are you able to gain muscle while on the low calories? I wanna be toned but not thin. Have any of you done this? Or is the caloric intake too low?

I'm taking in about 70 grams of Protein daily. My scale says I've lost about 7% of muscle. I really really really want to keep my curves. Is gaining muscle possible?

If not impossible, it's exceptionally difficult. I lost about 10 lb of lean mass out of the 100+ lb that I lost and that was with a reasonable strength training program along with overall exercise (primarily swimming), much as I had been doing prior to surgery. The 60-80 g of protein that we typically consume (upwards of 100 or so for some guys,) is a basic maintenance level - what we need to maintain our lean mass as opposed to building more. To add, say, another 10lb of lean mass over 6 months or so can require an additional 40-50 g per day in addition to a well developed, consistent strength training program. Whether that can be fit into a caloric deficit that will allow for the substantial weight loss that we need, along with other nutritional requirements that go along with muscle building is, dubious at best. From what I have seen, those that do get real serious about their exercise and conditioning tend to do what building they do after they get to goal and can increase their consumption. For the vast majority of us, the best that we can do is minimize the amount of lean mass that we lose during our loss phase. And, at 5'11", I suspect that 70 g protein is a bit marginal for maintaining your lean mass (despite the normal differences between men and women in their ratios of fat to lean mass); 80-90 g may be better (my target is/was 105 g to maintain the 150+ lb of lean mass that I carry.

I gained muscle mass when I was swimming like a banshee. I was solid muscle and no fat. This was right after surgery.

How did you keep your hair from falling out? When I swim I got to the salon with 6" split ends.