You MUST lower the humidity inside. Water on windows, skylights etc. is a warning sign. The same thing is happening inside your walls, just slower because of the insulation. If this is a filon walled TT or similar, delamination will be the result if you do not address the issue.... And just worrying about the skylight is NOT gonna fix the underlying issue.
If you have your TTs manual.... Read what it has to say about this.
You are on your way to ruining your TT at present....
And yes, many of us here have dealt with condensation in cold weather.
I use a 40 pint dehumidifier, or leave my vents and windows cracked, depending on how cold it is.