11lbs down in 1 month. Is that okay?

As of yesterday, I am 11lbs down from my original weight. I started at 210lbs (18F 5'0) a little less than 4 weeks ago and I'm currently at 199.0. I'm kind of concerned that I am losing weight too fast despite not feeling bad from my deficit. For context, my TDEE is ~1900 cals and my budget is ~1500. My main concern with losing this much weight this quick is loose skin. I already have stretch marks that I'm fine with but I would really prefer not to have loose skin.

Is this mostly water weight? Will the weight loss start to slow down in the next few months? Should I temporarily increase my calories budget to manually slow myself down? Is this a normal amount of weight to lose in the first month at my height? Thanks