If you had a routine before lockdown then try to keep it going. This should involve regular eating, sleeping and bathing along with any other important things such as work or chores to maintain your home. If the lockdown has affected your routine, try to make new one that will bring more certainty to the situation and help you cope with the situation.
Eat healthy and drink plenty of water throughout the day. Keep active by doing body exercises (such as push ups) or go for a walk. Another essential part of your health is your hygiene: wash your hands often and make sure you bathe regularly.
You may have more time on your hands now so why not take up a new hobby such as reading, art or playing an instrument. Your new hobby should be something that engages your mind but is also something you will enjoy.
Don’t lose contact with your family and friends when you feel down as talking to people is the best therapy. You can use Facebook Messenger, Facebook Rooms and/or Zoom to host video calls allowing for mass online gatherings not just for loneliness but also for fun and work purposes.
In your mind you could tell yourself that lockdown isn’t forever, it will eventually end and then you can get back to your pre-lockdown life.