15, 16 in just over a month.
5ft 10
176lb.
25% bf according to bathroom scales.
43.6% muscle mass according to bathroom scales.
Obviously you don't know how to count.
I put your stats into that calculator your provided and your maintenance comes out to be 2525, assuming exercise 3 times per week.
And wouldn't you know, 15 calories per pound would have given you 2640. Close enough since all of these are estimates anyhow.
Now stop arguing with me about what I am telling you. You have 2 extremly simple answers to your question of:
"How come I can't lose weight?"
A) Something is wrong, maybe with thyroid, causing you to have a metabolic slowdown. In this case, you should see a doctor.
B) You don't know how to count. I don't really blame you, when I was 15 I really didn't have enough patience to track calories, and thankfully I didn't care. I was having fun at that age.
At this stage in the game, seeing how much you need to be walked through this step by step and your refusal to except what maintenance should be for someone like you, I would bank on answer "B."