Well here goes
1 You did not stirr the paint,megga mistake,all the driers sink to the bottom inc pigment,so it will NEVER dry
2 You have hit the nail on the head when you said cold temp,as temp and humidity affect paint drying time
3 Wash off the hull with either white spirit,cellulose thinner or acetone none of these will effect the epoxy coating
4 reprime wiht plasticoat paint
5 Rub primer with 600 grit wet dry
6 Spray with top coat
7 Pat yourself on the back and go for a weel deserved pint