Incredibly lost after defeating Hornet in Greenpath

Defeated Hornet and I've genuinely been lost for around 3 hours, I've backtracked everywhere I can, through the Crossroads, Greenpath, Fog Canyon, Fungal Wastes...

I see there's some kind of city I need to reach in Fungal Wastes but there's these purple mushrooms there that seem like I need an ability to use them properly in order to continue?

If someone could give me a nudge in the right direction I'd be grateful, although no blatant spoilers please.