Hi fellow in house person :)
As much as I know how good a walk can be for us, usually the furthest I would go is to sit with my coffee by the open window or in the garden / balcony, as I live at an area where there is no nice park or anything to go to, and going outside would just make me even more miserable. But opening the window and letting some fresh air in while you take a moment to just be and not do anything can do wonders.
I also have a "power setlist" with about 10 songs which at the time I find motivating and listen to this on my way to work or first thing in the morning on a weekend if I feel like it's not going great and I want to get into the mood of being productive.
Most of my friends I know from online communities, so also for me spending a lot of time gaming or still chatting to people online before bed is spending time with friends. Even though I shouldn't be looking at screens just before bed, I still do it because for me it just works and it means quality time with people who actually care about me.
When I was having a hard time and didn't really know how to get from one day to the other I bought concert tickets so I always had something to look forward to and whenever I was feeling low it was a reminder to look at and say oh yes I still have this to go to and it will be great, I can't give up yet.
As others said before, breaking tasks and goals down into very small, easily achievable steps is very very important. You can feel lost or overwhelmed if you are looking at the big picture and don't even know where to start. So try to focus on things which are near, small and achievable things to do. Some days that might be tidying the entire house, some days it can be just getting up and changing out from your PJs.
And it's okay to have a bad day, or a day when you are not productive. Allow yourself to rest and do nothing, so your body and mind will both get a chance to recharge and set a small goal for the next day and make sure to do it, it will make you feel better as you did something to "make up" for one lazy day.
Appreciate the small things. I have a folder called "There are good things in London" and saved some photos there I took of sunsets by the river, parks, fancy cars I saw, a drink I had after a long day at work, so whenever I felt like I hated to live there, I looked at that folder to remind myself it's not all bad.