Lost access to my MacOS partition!!

First of all, I know, I know, I messed up.

I recently successfuly installed MacOS Mojave on my XPS 9560 on a new SSD. After using it for a couple of weeks, I re-installed Windows on a partition made in MacOS. I then installed Windows on it. But now I can't boot in MacOS anymore (the machine boots straight to Windows). Now this is where it gets spicy : I've lost my MacOS install USB that I used.

So far I've tried to install clover to another USB using BDU Tool on Windows. I've only made it to clover ONCE using an outdated clover pkg. Everything else fails (USB stick is detected under UEFI boot devices but does nothing). Only when in clover, I still couldn't see my MacOS partition. I can see the MacOS partition (700GB) in Windows.

What should I do?

Thanks for your help!