Feeling with less energy / tiredness & muscle pain throughout the body . been on vit b12 / d which is deficient , taking a month but not helping it ?

Many possibilities.: There are innumerable medical, nutritional and emotional conditions that include being tired as a symptom. These range from simple issues to those far more complex. A good checkup and blood testing would be a good starting point. B12 deficiency is a thought, especially if there's a consequent anemia. You may need repeat testing.