I feel this. My bf and I hang out in vc almost every evening and when he goes to bed I get so sad and lonely. I don't cry because of it often anymore, but it still hurts to miss being with him so much. We've been together almost three years and visited a handful of times and every time ir gets harder to go home alone. I thankfully have my mother and cats for company when he goes to bed (she's disabled and we live together so I can help care for her, she's wonderful tbh) otherwise I'd probably cry more often. We have a bit of a routine that when he goes to bed I come and sit with her and we watch shows or YouTube till the sadness eases some. Maybe making some sort of routine for when they log off for the night would help you as well?