If you aren't weighing everything (raw if it's something you cook), you don't know how much you're eating so you don't know your average intake. I cannot stress this enough: you are not currently aware of your intake. Weigh your food. All of it, except veggies (see below).
It isn't hard. Buy veggies, prepare veggies, eat veggies. Not sure how they're going to affect ketosis. It's not like carrots, broccoli, spinach, cucumber, capsicum, etc have a whole lot of carbs (or calories, for that matter).
Except the scale keeps dropping. Doesn't matter what you think when the facts are staring you in the face.
No shit. That's going to raise your energy requirements hugely. That said, whether it's actually all muscle is doubtful because 10 to 15 lbs of muscle is huge. At a guess, I'd say you've added maybe five pounds of muscle at the absolute most (which is still plenty, and will certainly drive up your energy requirements) while the other 10 lbs or so is water, glycogen and things like bone mass, with a little fat.
You're sitting around 130 lbs, right? You're not exactly super fat, but you aren't lean either, yes? That puts your minimum maintenance at 1800 cal/day. Now, that's obviously not enough, because you're losing weight, and losing it fast. Bump calories up to 2000 cal/day, and see how that works. If you're still dropping too fast, bump to 2200 cal/day.
Add 50 grams first: that'll take you to 2000 cal/day. Then if you need to bump up to 2200 cal/day, add another 50 grams. Consume them right before, during and right after training. For example, 15 grams half hour before, 20 grams during, 15 grams half hour after. Try to have the pre and post with protein but no fat. The intra you can have on its own, with protein or with BCAAs.