im in my mid-30s and have started feeling really tired of late. what should i include in my diet to help me feel energetic

Please get consultation from your doctor and get blood tests done. In the 30s women generally suffer from vitamin D, vitamin B12, calcium deficiency, anemia. Also, get your thyroid checked. If any of these is deficient, you will be given medicines and supplements by the doctor for replenishing them. Have healthy meals. Don't skip breakfast. Don't crash diet and skip any food group. Have lots of fruits and vegetables. Consume milk and milk products.