Can't seem to find comfort in our apartment or at home with my parents, any advice on how to get over this funk?

I've been forcing myself to stay in the apartment we once shared because I want to be able to keep on living there but it's been difficult since she's left. I might be able to find time to keep myself busy but as soon as I crawl into bed, the loneliness and anxiety takes over. I thought going home to my parents would help, but even there i felt uneasy. Everything felt familiar, but yet still so different. So, I'm struggling to find my sanctuary...where I can feel comfortable. I don't really know how to make one of these places my home again. Any tips, reddit?