[Sadeness]

Hello,
what I'm looking for is quite specific, but hopefully there're good novels like this out there. I'm fine with either series or stand alone novels.
The main points I'm looking for are:
-a fantasy world(magic, epic, myths or something like that)
-an interesting plot
-a strong female protagonist
-the most difficult point: a good sub-plot romance where the female protagonist at the beginning doesn't like and/or trust her future lover/partner
-The hero is someone like her mentor/master/colleague....
-the heroine and therefore the reader is not quite sure if the male lead likes the protagonist for a while
- no tragic ending

It would be a plus if:
- the heroine was in her twenties and the hero older than her. I don't mind big age gaps!
- the hero doesn't let his emotions shown easily and is strong mentally too.

Books I read like this that I especially loved are the Study series and Touch of power by Snyder, The Emperor's Edge series by Lindsay Buroker(hidden gem!), The blue Sword by Robin MacKinley, Crown duel by Sherwood Smith, the Black Magician trilogy by Trudy Canavan (didn't like the ending though) and Daughter of the Forest by Juliet Marillier. I've also read all Emily Gee's books and warbreaker and mistborn by Brandon Sanderson, Graceling and Fire. I'm sure I'm forgetting others...

I'm open for ideas even if the books you recommend haven't got all the points I'm asking for.
Any help would be great, Thanks!!!