Spoiler alert: you can't.
Lemme rephrase that, because I refuse to tell people what they can and can't do. I know so many people who are living their best lives while stuck at home for days or weeks on end. I also know some people who are struggling really hard with this. So, if you want to write, then do it. If you are a writer trying to write the next best seller remember this:
You don't have to. Not right now at least.
This is a really scary time, for a lot of people. Social media is full of "inspirational" tid-bits saying how if you don't come out of this lock down with new skills, speaking new languages, and the cure for cancer you did something wrong and you don't have motivation. Forget that noise. Don't let anyone tell you how you should grieve the loss of a normal life.
Our kids are home from school, turning us into teachers when maybe we suck at that. We're out of work, some of us and that makes us worry about our finances. There is so much in the unknown category that trying to be creative can be an insurmountable task. So don't feel guilty if all you've accomplished is keeping your dogs fed, and your laundry from eating you alive.
Almost all of the writers I've talked to have the same guilty faced "I had so many writing goals!" Myself included. With only 30,000-ish words left in my novel, and 2-3 weeks off work how could I NOT get it done? Then I stopped, and I really thought about what my days entail right now and I calmed down. Don't be so hard on yourself, no matter what you told yourself you were going to do because at the end of the day we are all sitting here in the midst of an international crisis wondering what tomorrow will bring.
Write on, friends. Tomorrow will be alright.