Writing is indeed a very good outlet when you’re missing your spirit spouse but he is too busy doing important stuff to stay for longer periods of time with you. I’ve actually been doing the same since last month. Not a spirit spouse, but a spirit I have feelings for all the same would come by less than usual and damn, could I relate to your sadness and lack of motivation the first few weeks.
The confusion and heartbreak plagued my mind too until I got sick of myself moping around and decided to do something: writing a poem dedicated to him every day. Soon, I was able to write poems about random topics, even coming up with 2-3 in in just a day. I also went back to writing in my discontinued diary and while we can’t help the feelings of missing them, wondering what they’re doing, wishing they could be with us like a normal human couple, letting it all out either in actual pages or MS Word + making something creative out of all the feelings = priceless. I remember feeling proud each time after writing when really, it was just a simple piece. The sense of accomplishment and productivity definitely eases the negative thoughts and feelings. Maybe continue unfinished projects or try out a new skill/hobby/interest?
Also, I’ve noticed that reaching out to others who make also make you feel loved and appreciated helps with the feelings of loneliness when he’s not around. Now of course we can’t do the meet-ups and gatherings due to the pandemic, but maybe send a message or two to your family? Video-chat good friends you have not seen for quite a while? Since I live with my family, I’d busy myself with helping them out more than usual or taking care of my younger brother. Lately, it’s as simple as watching the news with my Dad, exchanging opinions then switching to watching a Netflix series we both love lol. I’ve noticed that you are also quite dear to the BALG community: why not message the ones you’re close with here or start a journal about the very matter you are asking about? That way, not only you’d have an outlet, you’d also be able to interact more with your friends about each entry update. Pretty sure they’d like to help you out, cheer you up or discuss possible ideas which can ease your worries about your spirit spouse once and for all. Long story short: never forger that you have a support system.
I may not be a part of this support system for I suck at making friends in general but contrary to your post’s last sentence, I’d still like to let you know that you’re not alone all the same.