Isn't too thick possible a VG issue? For using Cartos, I have read reviews saying use no more than 30% VG.
And you know what too? Like I said below about my taste, it might taste off to you right now. Whatever flavors you are using now, put them to the side for a while and revisit it later.
Part of the thickness may be the ratio, but I think part is the heavy flavors, too. I think I need unflavored nic juice to mix with it. They were very new when I tried them, though.