This is just for information, I have no idea if this is a good thing to do and don't do it before somebody here who knows about this things has told you it's ok.
I have been stuck in this a half day, not been able to come into xfce, tried all fixes mentioned here but not working. I cleared up the computer, did necessary back ups of home and so on to prepare for a new install, I don't have time to wait, must have the computer working.
Just before starting a new install i remember that I have experimental repo enabled so I invented a desperate command that I didin't have no idea if it is possible to do but apt -t experimental full-upgrade
apt -t experimental -f install
really did it. Maybe I have done something that will hit me later but for now I have my computer up working again without re-installation.