Good that it's generally pain free & that the thrush has gone - very well done for already having reached the 5 week mark.
I had some initial issues with tongue tie, mastitis & blocked ducts, so not the easiest ride to start with but, when that all got sorted out, I did still get sore nipples when DD fed for hours at a time. The soreness wasn't really pain exactly, but was really uncomfortable and my nipples would definitely feel used & abused! After the 6 week growth spurt and some of the evening cluster feeding, I had monents of wanting to send my nipples on a long holiday to recover :)
I think, and this is only my opinion, that even if the latch is perfect it does take some getting used to, especially if your LO feeds often - the fact is that nipples are sensitive and I think some need more 'toughening up' at the beginning. Mine definitely did. Also, mine were more sensitive just before my period would have started - hormones maybe?
Now, at the 13 week point, DD still flails around, spits the nipple out repeatedly, sucks it back in etc, but there is never (ever) any pain in terms of the nipples themselves. The blocked ducts are an ongoing battle, but that's another story...
I've also found breastfeeding to be incredibly rewarding, but incredibly challenging. Keep going though, you're doing brilliantly and it won't be long until it's mainly steps foward with fewer & fewer back.