Yorkie sensitive skin flea prob

[cas3yl33]

I have an older Yorkie. very sensitive skin..lately extremely bad flea prob. I use dawn dish soap, instant flea killer.
I know bathing Maddie, my Yorkie, frequent is not good. I have no other thoughts about giving her relief from fleas.
her skin has become bright red, past irritated, blotchy? and there's sore type things. looks like weird ant bites & recently noticed a dime size hard white mass, idk what to call it, on her front paw.
I possibly can def be over thinking these issues. worried & want to give her relief from the scratchy fleas.
I had to sent my first Yorkie to heaven. neighbor accidentally ran over him leaving my yorkie pinned under the truck tire. no.broke bones, road rash & hip out of place. turning into diabetics.
help? after my first Yorkie went to heaven, my sister saw a posting regarding Maddie. a lady needed to get rid of her "bc it was her aunt's friends sister cousins dog" and only vet history from when she was a puppy. two vets one in Gonzales the other in Mississippi.
I'm not too informed about her life b4 me. nothing wrong w her.
all she does is scratch, try to scratch her bottom & then she lets an aggravated bark out! maybe the dawn soap not agreeing w her skin or is there a much bigger problem??? there is loss of hair on back, her scratching is making skin vulnerable . I've also noticed since I got her, almost two yrs ago she is not two, these odd shaped black spots appears randomly on her skin.
being a single mom & going thru health issues w my first Yorkie, am I over thinking this?????