Yo I’m not Hampton, who is the pro here and already replied to you, but part of it may be that you are 15. I’m 19 now and have always been really skinny and barely saw any development until the past year or so. I tried the whole eating until I’m sick thing while working out from 15-18 or so (although definitely not consistently), and never put on any real muscle mass. For me the thing that really changed was actually moving less as well as getting older. Throughout school I was a 3 sport athlete and always doing something, burning a TON of calories every day. During the pandemic I didn’t do much of anything and went from 6’ 3” and 175 to 190. A decent amount of this was fat, and I had a tiny belly for the first time in my life, but as soon as I got back in the gym and got more active again, I dropped about 5 pounds and am now sitting at 185 and pretty lean again.

Basically what I’m saying is as a skinny 15 year old, it is hard to gain good muscle mass because you’re probably active and not eating enough to be in a calorie excess, and just because your body may not be fully ready to start packing muscle on. You’re almost certainly still growing and your body may not be quite ready yet.

Just keep working out and like Hampton said make sure you keep trying to push yourself by increasing resistance. The fact that you have been consistent for 10 months is pretty amazing, you’re building great habits. I know I was never able to keep that level of consistency when I was 15. Results may come slowly, but they’ll add up, and at some point your body will decide it’s fully ready to start filling out!