How is he managing?

Ooooh, I am gnawed by terrible doubts. DS is 20 months old. He does not eat a lot of solids, but is very fond of pasta and fruit. He does not get much other liquids other than breastmilk.
But lately I've had nipplepain. I think I might have thrush
DS is sucking strangely lately. He will suck very lightly for ages. He does get some milk, I can see it at his tongue at the breast... it is as if he was drinking from a chewed straw.
And he rarely stays longer than 5 minutes at the breast.
What is going on? Should I see an IBCLC?
I am worried that he won't get enough liquids, but I don't want to hamper my supply. In my desperation I pumped... and got about 1 tablespoon out - not very comforting.
He does have a pacifier to sleep. I never got him off that for naps... that darned nurse that popped that pacifier in his mouth when he was 3 days old - aarrrghhhhhhhhhh!
I just don't know what to do! Is it maybe my fertility returning? Is DS getting enough milk?

I'm so confused and worried