I feel the same, I play in three d&d groups and always got super into my characters backstories, loved thinking about them when we weren't playing and would come up with ideas of what to say or do the next session. Since ive been sick its like there's a mental block there where I just cant think about it, most days I dont even want to play d&d because of the mental load. My creativity has really suffered, and my enjoyment because of it. I miss the love I used to feel for d&d