diaper rash 😓

my son has a very bad diaper rash, he first developed it around 2 weeks ago, but it wasn’t nearly this bad. tonight i was changing his diaper and i noticed that it developed white blotches! i have no idea what could have caused this. 2 weeks ago he just turned 6 months, we gave him baby food for the first time, if that could have any effect. he’s teething as well. i change his diapers as soon as i notice it’s wet or soiled, and i ALWAYS put diaper rash cream. we’ve tried different creams, diaper brands and even going up a diaper size. it doesn’t seem to bother him at all, no fussiness/fever, but it looks very painful and i feel so bad :( any one else’s baby?