Please advice mee!!

Hi I’m a 16yo female, about to turn 17 in 8 months. I weight 50kg and I’m 5’2. I have a hypermetabolism which doesn’t allow me to get fat easily or grow breasts. I am roughly a 34A. I have moderately tiny breast that fits a palm perfectly but it’s very pointy and “pyramid-ic”. Their also far apart. I’ve been trying to grow them out by eating more. It’d grow and stay a little big for a few weeks or days then it’d melt away. That usually means I lost weight. Right now, I’m at the “default” size which, as described earlier, fits a palm perfectly. I hate it. It honestly looks really weird and I’d love to make them more rounded in shape. I’m very concerned about maybe I’m micromastia or tuberous breast. Any advice on what I should do to grow them out? Should I even be concerned in the first place?