the sweating is from moisture getting in and condensation is building up when it warms up, first off you need to get the inside dry whether you use compressed air of whatever and then I would use some clear silicone sealant and go around where the lense seals to the housing, also check your bulbs that they have the o-ring and are correctly seated in the plug.
My drivers headlight leaked to the point when I first bought the car I washed it and there was 2 inches of water in the housing, ended up busting the bulb when I took a curve, guess hot bulb and cool water dont work. The way I fixed mine is by replacing the headlights, but since you have diamonds I would definitely make sure to seal them bad boys up really good.
aftermarket lights where the two halves are joined together are only spot glued. If you have a hot glue gun you can go all the way around the parting line that joins the two halves and weld it shut perfectly. I had to do my headlights and the hot glue when it dries looks undetectable and cleaner looking than silicone.