Remember that you're building muscle, which weighs more. I have the same problem with not eating enough and being in constant starvation mode, so my body holds onto ever ounce of fat. Have you done your measurements? I find that when I work out a lot, I lose inches but not necessarily a lot of weight. For example, in 2011 I started just concentrating on exercising my mid-section and lost nada...zip...zero, but went from a size 12 to size 10 pants, because I tightened up my belly and butt. I'm doing that again right now, because I feel like if I could just get down one size, I'd be encouraged to do more.
Heading to Healthy One Day at a Time!