Bro you are underweight in terms of BMI metrics you should bulk. You might think your fat/overweight but that’s get your mind playing with you. I would start working out and eating 300 ish ( or more ) calorie surplus to get that physique. When your skinny you can get great physique as long has you don’t eat straight junk food.
I’d consult a doctor. The problem is that if you have no fat stores I’m pretty sure your body starts turning to muscle for energy which will obviously decrease your muscle mass. Your heart is muscle btw. So it’s very dangerous. Idk if your body will start eating your heart since it is a muscle but I wouldn’t take the chance. You do you though!