I’m looking for a manga where the first love is not the end love. That the MC goes through heart ache and trial and error to find their happy ending. I’ve never seen something like that, and I feel like it would be more relatable/realistic than middle schoolers falling in love->everything is perfect->the end.

It's not trial and error but...

Ookami Shounen wa Kyou mo Uso o Kasaneru

in need of romance?
uncommon, sad, sweet

Maybe Scum's Wish?

Shitsuren no Susume though it's more comedic

definitely kimi no iru machi

Thank y’all for the suggestions. I’m already reading one now as I respond, and will definitely get to the others in short order! ❤️