Recs for grumpy/sunshine, he falls first and is obsessed, she heals him emotionally

[Teal]

Favorite:
Caught Up by Liz Tomforde
Hopeless Elsie Silver
One Month Boyfriend by Roxie Noir
Wall of Winnipeg and Me Mariana Zapata
All Rhodes Lead Here Mariana Zapata
Forget Me Not Julie Soto

[Mady]

I second the hopeless by Elsie silver

[Marilla ☘︎]

Dear Enemy by Kristen Callihan
Melt for You by J.T Geissinger (reversed age gap and kinda reversed grumpy X sunshine too)
Blind Side by Kandi Steiner
Still Beating by Jennifer Hartmann (dark romance. Check TW)

I don't know if these are exactly what you're looking for, but they were the first books that came to mind. Dear enemy is probably the closest to your description though, if I remember correctly.
Hope it helped some :)

[Bettina]

the only one i’ve read like this is probably… Twisted Love by Ana Huang!