For me, I had to start small and had to do stuff at home even if I didn't want to.
I started by reading books instead of using any type of technology use(computers, TV, phone, etc.).
I then did a small workout for 20-40 minutes at home each day. You can also try meditation, yoga, etc. (I love Kundalini Yoga).
I taught myself how the stock market works so I can learn about investing.
I learned about the confusing jargon that is medical insurance and was better prepared when picking a plan the next year.
I started to volunteer - which seemed overwhelming at first, but I do it at an animal shelter, and it actually relaxes me.
Once I was able to get some stuff done at my own home, I then knew I could easily do stuff outside of it. I started to go on hikes; I would go fishing and really just being around nature, in general, helped me.
I know you want to leave your place and I mentioned I stayed in mine at first, but I think you could easily do these activities outside at a park or really anywhere. I guess depending on what your motivation is will determine what you might do. If you just need to shake the anxiety & withdrawal for a few days/weeks, then any kind of distraction for an extended period of time should work. If you are looking to get back to "normal" life, then I would suggest trying to build a routine or some kind of consistent plan each day.
Start small - doing something for 5 minutes is a huge win vs. putting it off and being miserable sitting at home. Then the next day try 7 minutes or 10 minutes and just try to build off of each accomplishment. The worst enemy is always the own mind telling you and worrying about things that are absolutely untrue, haven't and probably won't happen.
What kind of hobbies, interests, passions do you have? How about something you wanted to try but never have or even something you know absolutely nothing about and just go learn about it.