Sounds like Nike... "just do it".
First, it has to be your goal to get out and do things, not his.
So spend some time thinking about whether you do want to do things or are happy not doing things. Many people live quiet lives because they want to and like to.
If you decide you do want to get out more and do things, think about what things you might like to do. A trip to the library? A walk in the park? A movie? A community event?
Then when you have decided what you might like to do, giving yourself plenty of time, think about when you might like to accomplish this. If your deadline comes and you can't do it, just accept that without any self-judgement or self-criticism and set a new date.
Once you've reached your goal, Celebrate! A Starbucks coffee, a movie rental, a new book, ....
Keep practicing, keep doing what you can, keep accepting without judgement if plans need to be changed, keep Celebrating!
I hope you can also find a therapist to talk to about how hard it is to find motivation and energy and how you feel.
hugs