No matter how big or small, always appreciate the things you have in your life. This will distract your mind from what you lack.
Meditate at least 15-20 minutes daily as it will help to keep your mind calm reduce stress & will give you happiness & peace.
For internal as well as physical happiness the most important thing is to have good company, people who uplift you & support you in every situation.
Always pamper yourself. Keep yourself encouraged and treat yourself with care, especially in tough situations.
Connecting with nature will keep your mind calm, so take a walk outside daily wherever and whenever possible.
In such a tough schedule and work days, it might be difficult to take time for your hobbies. But you must do what you enjoy the most whether singing, dancing or anything else.
Physical exercise would be of no use if your mind is not at peace. So focus on things that keep your mind calm.