My energy levels feel unpredictable and out of my control

Energy levels are impacted by many different things. It is directly linked to sleep (quality and duration), nutrition - not too much sugar, but also enough micronutrients, stress levels, physical activity (too little causes fatigue), substances used, cognitive demands, overall mood stability and even the environment (chaos can be over-stimulating). It is likely that these things are fluctuating and that might be dragging you down mentally. The things that you can change yourself include getting adequate sleep, nutrition and physical activity. If there is another underlying mood disorder such as depression or ADHD, the right diagnosis and treatment can be helpful.