It feels impossible to move on from grief when you're trapped in bed/at home with nothing but your thoughts

I had a falling out with my best friend almost exactly 2 years ago and I cannot come to terms with the grief and loss. It's been so heartbreaking for me and I can't seem to release the pain without reconnecting to others or being able to spend time outside the house in meaningful and therapeutic ways. I'm just stuck between these 4 walls with nothing but my thoughts :(

I don't even have the strength or desire to be in therapy any longer as I did that for over a decade and can no longer see my old therapist that actually helped me.

I just feel frozen in time, like I am reliving the same day over and over like Groundhog Day.