Hi,
I can't remember much about this one so any help will me amazing.
It is au
Buffy and spike are together and I think she stays at his house sometimes(I'm not sure about that)

Buffy is working at a bar or club or restaurant.
And eventually so is angel.
Angel rapes or beats up buffy and leaves her in an ally way.
Buffy's father doesn't like spike
Buffy has an abusive father and buffys mom is also afraid of him

Hi, it makes me think of Father Knows Best by TammyAsh666 aka TammyDevil666 and on EF.

Summary: Dawn Pratt is tired of all her friends having a thing for her father, so she stops inviting them over to her house. She takes a chance on Buffy Summers, a new friend of hers, not realizing that was the one girl she never should have invited over.

It fits everything except that Angel does work with her but he's the one who finds her in the alley behind the Bronze, not the one who assaults her. Hope it's the one. 😊