Agreed - Lansinoh is great for cracked nipples from bad attachment (don't care what anyone else says, it saved my skin when DS had TT!), but it's not going to help with thrush.
I find the Daktarin oral gel after every feed and in between works fantastically, as well as orally dosing the baby's mouth. The pharmacist will ask you if you've seen a doctor about it and if you have then just tell them so (even if the doc hasn't suggested the gel!) and that it's for nipple thrush - as soon as you say 'nipple thrush' they back off and assume you know what you're doing. They're just afraid of you giving a spoon dose to a baby under 6 months old, but the stuff is fine if ingested from it being smeared on the nipple (and it's not smeared fresh for them to ingest, anyway, it's applied well before a feed to deal with the thrush on the nipple, not in their mouths IYKWIM).
When DD was first swabbed and it came back +ve the doc suggested a thrush CREAM and said to wipe it off before every feed...this was so inconvenient when out, and I was out a bit (was just before Christmas!), so I just didn't use the cream till I got home, which could mean a once a day application. Doc obviously didn't know about the gel, or didn't realise it could be used more safely than the cream?
Anyhow, if you haven't been treating it, be prepared for symptoms to get worse before they get better...and they DO get better!! Before you know it you'll forget what it was like