winter camping!

As some of you might be aware, I am living in my cargo for the duration of what ever and need some help.
Moisture is my number 1 problem. I use a blue flame heater which works great but need to get the walls insulated for next year. Doing my homework now and was wondering if you have any suggestions as to how to insulate the trailer. Right now it is 13 out at 4 am and the walls are wet on the inside skin of the trailer. Inside temp is a comfortable 64.
Thinking that putting the blue 1 inch Styrofoam insulation is good for the voids between the studs but to seal the gaps next to the studs is my question. Should maybe I put up plastic as well to keep the moisture from reaching the inside of the wall skin as a vapor barrier. I figure that by adding the insulation and to get rid of moisture I would leave the vent open wider.
Moisture is my number 1 problem. I use a blue flame heater which works great but need to get the walls insulated for next year. Doing my homework now and was wondering if you have any suggestions as to how to insulate the trailer. Right now it is 13 out at 4 am and the walls are wet on the inside skin of the trailer. Inside temp is a comfortable 64.
Thinking that putting the blue 1 inch Styrofoam insulation is good for the voids between the studs but to seal the gaps next to the studs is my question. Should maybe I put up plastic as well to keep the moisture from reaching the inside of the wall skin as a vapor barrier. I figure that by adding the insulation and to get rid of moisture I would leave the vent open wider.