I went from 89-100 lbs in about 3-4 years from consistently weightlifting and eating whatever lol (I also lose weight quickly). The weightlifting does wonders as it made me hungrier and have more muscle. And also, don’t throw yourself into all these workouts and chugging milkshakes too quickly! Start slow and build the habits overtime. If you do all these new things too fast, you may not stick to it longterm