Where to start?

We are just starting out with TSG, and we desperately need all of the skills, because we are struggling big time with behavior and lack of connection. We tried jumping right in as soon as I felt like I understood the basics. My 6 and 7 year old boys in particular are out of instructional control a lot because they won’t follow instructions and won’t do any chores, and they don’t feel like it’s a big deal to lose privileges. I’ve taken away treats, most toys and screens and outings…. They just stay home and find things to ruin and the potty language has been out of control. They can’t seem to get out of being “out of instructional control,” it feels impossible, because they can’t be nice long enough before they’ve earned more chores and then won’t do them. Even if it’s super simple like picking something up off the floor, It’s a huge power struggle every time I try to do a correction. they fight me and won’t stay in a calm down spot unless I physically hold them and then there is biting and screaming. Help! Where do I even start? They are fine as long as I don’t ask them to do anything and never say no…. And there is also lot of negative attention seeking and potty language and bad behavior anyway. And they earn chores but I can’t get them to do any of them unless I lock one of them in the bathroom and don’t let them leave until they clean a toilet or something, but that just feels like such a power struggle and I have to stay with them to monitor them so they don’t waste all the bathroom supplies and make a bigger mess but my ears can’t take the screaming. Sometimes I have to take care of the baby and can’t be doing that for hours. The simplest requests can turn our whole day into a battle and so I’ve been trying to pick my battles but then they are worse from the inconsistency of which problems I’ll deal with. It’s everyone against mom over here and I’m losing. I think we definitely got off on the wrong foot. The first couple of days were good with all of the extra praise, and they enjoyed the kids books, but then I started correcting and it feels like things are worse than before. I know calmness and pre teaching and praise are important and I’m doing my best with those. I’m just stuck with them being out of instructional control with no end in sight. Help!