[ubuntu 16.04] impossible to reinstall bcmwl-kernel-source on Dell XPS 15 9550

Hi,

I dual-booted Windows 10 with Ubuntu last week, and it worked like a charm for 5 days.
However, my WiFi coection tued slow at a point, so slow that it was taking me 2 minutes to load even a google search page.
I decided to search for similar problem, and I ended up using the command:

sudo apt-get remove --purge bcmwl-keel-source

I tried to fresh install the bcmwl-keel-source.deb package, but either it freezes
or a fatal error shows up with the following message:

modprobe module wl not found

Thank you for reading!