28 month old will not stop whining and crying about anything and everything. HELP!

She’s on a great diet, focus on protein, multiple supplements, electrolytes daily, lots of play and reading, do not helicopter parent, she’s incredibly advanced, adventurous and independent but her emotions are WILD. We know she’s an HSC (highly sensitive child, reading lots on this now) yet it seems like none of our approaches are working :/ she’s continually having melt downs. We are at a loss and I’m literally feeling defeated and highly discouraged with my husband:( idk what to do anymore. We’ve tried it all 🙃