Say I hit the double xp limit, but I still want to continue playing, will I lose my double xp matches in the form of 0xp?
Yes sir, I made that mistake and lost a few matches.
Because when I first hit the cap, I did not get that BIG HUGE WHITE screen popping up saying I hit my limit. 
Yeah…oh well…but seeing as I was silly enough to buy that dbl xp, kinda wish I had it back.
I only use a few at a time now and keep track of how much xp I’m going through in a night. Live and learn.
150k xp is the cap remember.
Well that sucks, I don’t remember how much XP I’ve earned for today, guess I’ll have to stop.
.-.