What should I read?

You've probably read it, but The Midnight Library by Matt Haig is very good.

Where the crawdads sing

The enchanted April

All the light we cannot see

Sorry just checked OP. I don’t do fantasy novels so no help

I assume that you have read His Dark Materials?

Not sure if you'd call this a 'happy ending' but it is uplifting:
www.fantasticfiction.com/t/john-twelve-hawks/fourth-realm/

I've also found Marion Zimmer Bradley's fantasy and 'alternative view of history' books interesting.

And, although not fantasy, an insight into 20th century history through the the eyes of a very interesting detective:
www.fantasticfiction.com/w/jacqueline-winspear/

Hope you find something!

I have just finished an un-put-downable book called "Three Hours" by Rosamund Lupton. I can't recommend it highly enough, and I'm still thinking about it even though I've now started reading something else.

I loved Three Hours.
Madhope, have you tried any of Sarah Rayne`s books? They`re psychological thrillers with a touch of fantasy about them.

What about "The Witcher" by Andrzej Sapkowski?

Maybe Angela Carter would fit the bill?

The good thief. - hannah Tinti.
Carlos Ruiz Zafron books
Life after Life - Kate Atkinson
The master butcher's singing club - Louise Eldritch.
The tenderness of wolves - Steph Penny
The Alchemist - Paul Coelho.

I agree that Three Hours was a great read. I could visualise it all.

I am three quarters through Cloud Cuckoo Land by Anthony. Doerr who wrote All The Light We Cannot See. Five different different main characters, all with different stories but all linked together. I am really enjoying it. One of the story lines is science fiction. I am really enjoying it more and more as the plot evolves.

10 Effective Ways To Learn From Books
www.bookavatar.com/how-to-learn-from-books/

The early Tom Holt books are hilarious - in the genre of Terry Pratchett.
I love Barbara Trapido - always has a good ending.
Mary Welesly

I've just finished The Central Line by Saskia Sarginson which I could not put down. Brilliantly told with a happy ending. Not fantasy but a light romance, of people who stumble upon each other, a widow and her two children.