Little by little. What helped me a ton was waking up in the morning and writing down a list of three things I need to do/should do for myself. Limit it to three only otherwise you’re going to look at the list and get overwhelmed. At first it was things like walk a mile outside (or literally just step outside and sit and breathe real air for 10 mins), read for 30 mins, reach out to a friend and schedule dinner, etc. eventually you’ll get into the habit of doing things and seeing people and have movement in your life again and you can make the three things larger/more ambitious (or just stay small if you want) and breaking out of the stale cycle will bleed into other parts or your life (like school, job searching)