Unable to login in Trisquel

I was attempting to minimalize resource usage by unistalling packages and installing their minimalistic counterparts, till i replaced lightdm with xdm display manager and restarted the computer. Now when i log in i see is a black background and a cursor. I tried everything, and the GRUB command line refuses to let me in even if i type everything correctly (it never worked anyway). How to gain access to the command line?

I was using the xfce desktop environment (Trisquel mini)