Almost 20 years ago, I lost my fiancé to an undiagnosed heart condition and he passed away suddenly in our home. I was really young so I dealt with it rather poorly, with substance abuse and avoidance which was obviously not the right choice.
For me, once I allowed myself to feel my grief and just focused on the small snippets of happy I could find in the day, I began to breathe a bit more. It also really helped to talk about my fiancé and the good memories we had, big or small, with others who knew him. Every new day brought just a bit more air into my lungs and before I knew it, I was able to feel like I was living again. Albeit living with a heavy weight around your neck but still, living.
One day you’ll get there but focus on one step at a time, find the small joys where you can (and try not to feel guilty about finding said joy), and give yourself the same grace you’d give to a loved one who’s lost someone they love. Grief has no timetable and as someone said, it’s not linear, but you will make it through to the other side someday.