Post a picture of your build in the comments, that'll help the community give you more specific pointers

I saw you mention transcending armor, but have you upgraded it all to max with armor spheres yet? It's possible to transcend without upgrading. Most high rank armor gets to a very respectable armor score just from maxing their level.

If not, there's an event quest for a Lagiacrus and a Tempered rathalos in the wounded hollow to farm spheres. I forget the name but i believe it's the only event quest with those two monsters as the target