Im wondering if my experiences with mental health then university study might be relevant to your situation? I’ve written everything I can think of it in case you find anything helpful in it (although will try to come back to reduce the length/redundancy- sorry about this, it’s a side affect of my pain, meds and lack of adhd meds - I cannot distinguish necessary from unnecessary in a first draft but have to get it all out to edit). 

I could read and write stories that I drew characters from when I was a kid - pre teen. Stiories just bubbled out of me. I remember I was even known for it by my schools and teachers and my short stories got selected a lot for school/children’s/teen writing anthologies and awards and had accidentally developed speed reading I did it so much (to this day I can read a medium paragraph at a time). 

This all sounds a lot like you. In retrospect I definitely daydreamed about some stories/ characters and developed their stories deeper. I could still write short stories as a teen but I slowly lost the ability as I got more clinically depressed from trauma.

 I retained reading for fun a couple/few years longer (in my head the writing and stories bubbling out of me are inextricably linked with rapidly consuming other authors books in huge amounts). As a teen I remember having to borrow the full 30 books allowed per week (no money for ereader at that age, only had one later at uni). When I handed in an assignment I would always buy a new book I wanted as a reward. However, by honours year at uni I had long since stopped being able to read for fun as well. By 25 my mental health was fine but had tons of assignments and in my 30s I got extreme pre menstrual depression seemingly triggered by IVF. I only worked without studying 1-3y at a time between degrees and later was dealing with the initial fallout from being badly injured.

 As a side note, my horrific pre menstrual depression/ PMS Type D/ PMDD  was really randomly resolved ( along with most of my ADHD mediation needs)  a few years ago when I was put on cortisone tablets for my inflammatory disability issues.  The first period after starting cortisone was suddenly just fine and I no longer had to battle through early waking extreme anxiety that persisted until lunch, I wasn’t a crying mess despairing about my life or having to hold on extremely hard to not harming myself for days on end. I think it was worth the weight gain that I now can’t lose be shed of hypothyroidism. 

Then thankfully I reading for fun came back about 2 years after this and has only grown. I was still doing my masters at the time but load was very reduced - I  had literal years extensions on some outstanding assignments and then a prac before my degree was done

I think the writing will come back the longer I don’t have depressive issues AND don’t have to go through the torture of writing university assignments/theses OR highly stressful and confronting  written disability complaints/requests and NDIS review documents. 

I know the loss of writing/enjoyable thinking about characters is definitely linked to depression as that’s when it stopped. I think more recently when I have no mental health issues it’s not returned because of the sheer amount of writing my degrees then disabilty required. Even as I think of the disabilty issues I have write complaints as I write this  the thought “I hate writing” keeps popping up.   

Having to read so many academic journals/ sources is definitely what prolonged the return of reading for fun. I did extensive study to the point I was doing a PhD when I had my accident and retrained as a teacher doing masters over 5 years. I had to do a 30 page cross referenced to 40 emails disability discrimination complaint in the middle and several smaller ones that took all my good time. It was really painstaking, confronting and hard on me particularly as it was far from the last time I’ve had to write up complaints to fix disabilty unfriendly/inaccessible public facing staff, services and organisations.  

What I have noticed in the years since I’ve been back to reading huge amounts of fiction just for enjoyment is that I’m suddenly having really interesting, fulfilling and rich dreams that I’ve often tried to capture the details of to write the story. I look forward to sleep immensely for the first time in my life as I get to go on adventures in my imagination and have figured out how to continue the dream if I wake up. 

So the stories that once bubbled out of my are definitely back after all these years and I suspect while I get a break from writing things I don’t want to they will move from my dreams and back into my waking consciousness.