Why do I have so much of this?

It's a mucus produced to clean out your . It could possibly indicate an infection or that something is irritating you. Consider talking to a GP. Tampons do suck discharge up, or at least help to. The mucus is also produced when you're, for lack of a better word, horny. It acts as a lube for . If you've recently started having or thinking about more often it could also be the reason.