Do whatever makes you happy. Even if it is cooking or working out. Try to follow a routine. It will take time. But everything will be worth. Do online courses of your interest. Read a book, cook, dance. The most important Write a Journal.
If you are a morning person you could try exercising or doing houshold chores.
If a night person , try cleaning you cupboard, desk.
Read a book
Learn a new language or a new skill.
Take up a good habit like waking up early, or reading a book, exercising, meditating and many more.
Use the available time to up-skill. Learn skills relevant to your field of interest or Start a blog.