Latching

Hello ladies, I have trawled the pages to 60 something and I can't find any answers, my 5 week old boy is breast and bottle fed, through the bottle because the latch is so appalling and he cannot get a sufficient feed, I'm sure it will get better as he gets older and bigger and can open his mouth! My question is when he comes off my nipple tip is white! Don't think it's thrush because Oscars mouth is ok and I have no other symptoms and it returns to its cracked bruised state in no time! Any suggestions?