Why is my filament pressed together at the nozzle
As per attached picture I can see that the issue source could be:


the ptf tube is not inserted to the end of heat-break, or it is not straight-cut at the end - see this video for help
the cooler on the hotend is not working properly/not installed and heat goes up to the throttle and melts the material
an object in the nozzle that blocks the flow (usually a ptf tube particle that probably melted) - clean/replace the nozzle