Is this mastitis?

Help.. I've been suffering with a pain and discomfort in my left boob for around 4/5 weeks now when I spoken to the health visitor(UK) and infant feeding support worker they said it could be her latch however she's got a mouth like a hoover. Loves boob and we've never had any problems.. Each day the pains been getting progressively worse and yesterday I came up with a rash? But my boob was sore and lumpy and as the hours go by its getting worse. My boob is so painful, I keep putting my little girl on there to feed and keep pumping as I was told to do so by my gp.. But its getting worse.. Any help would be great thanks

1st 2 pics are yesterday

This morning

This afternoon