I have changed up my exercise in the last month actually. I was weight lifting all along (even when I was training for my run) and am now doing Crossfit (with a bit of running in between). I think I may have to either decrease my calories and/or up my protein intake because of all the intensive weight lifting I'm now doing. My concern was undereating and stalling my weight loss that way as well.
I actually don't drink any diet soda (or any soda unless it's soda water), thesame7lbs. I found it to make a big difference too. I eat as close to natural/organic food as possible so no artificial sweeteners for me.
I'll try dropping my calorie range a little guys. Thanks for the help