08 Ford Fusion 2.3 Overheating, NO HEAT

So my fusion has been acting rather strange. I'll warm it up
and drive for about 5 minutes in the city and at a stoplight it
will start blowing cold air and eventually overheat and
coolant will leak from the reservoir. Most of the time if I
give it some gas or take off from said stoplight the temp
gauge will go back down and start blowing hot air again.
Happens mostly when under freezing temps.