Tell me I’m not the only one struggling to be a step parent

So as bad as I feel about it, I’m struggling with my SO kids. They just get under my skin most times. I think it’s because they have no structure and the parenting styles from their mother and my SO is just totally different from mine the parenting style from the mom is so ghetto, I mean I grew up in the ghetto myself and I worked hard to raise my kids to have manners and to behave and speak properly in certain spaces. These kids have not been taught any of that and it bothers me oh so much. I know it’s not the kids fault but OMG I’m really struggling here. The oldest one (16 yrs old) has stole money out of my purse, they cuss ALOT, they make a lot of mess and barely clean up after themselves I’m always finding soda cans or water bottles kicked under my couches or tv stand. The middle kid (13 years old) breaks my 9 years old and 1 year olds toys. Idk sometimes I feel like an ass for feeling like It’s hard to like them tbh. Is this normal? Please tell me I’m not the only one who struggles with step kids… No hate please. Maybe some advice would be nice instead of criticism.