Yes, I know how you feel.
We've been having a difficult time with dss (I'm not married to his dad, so dss is shorthand, but I don't consider myself his stepmother) where he has been suspended from school, found with hard core porn on his phone, stolen something and reported his stepdad to social services. Amongst other things too tedious to mention.
He's 14.
Now, all this obviously comes from a place of attention seeking and I am intelligent enough to know that. But I am incapable of having enough input to really help put anything right - it is his birth parents who need to do that, but his mother doesn't seem to be very interested and DP is incapable of following through on any course of action we agree (having read some of the posts, I see this is a common theme!).
He is in the US this week for work, I was working at home today so dss was here this evening, we had various 'issues' which I have dealt with. DP texted later and asked how the day was, I told him and he started text-telling me how else I could deal with it. I texted him that if I am not to be trusted to take the decisions then maybe he shouldn't leave dss with me when he goes away. It's was fine, he apologised and said he was trying to help.
dss was OK later this evening, we had a nice time in front of the TV chatting. And he went to bed OK and even unpacked the shopping without being asked (this is almost unheard of). The issues were more logistical today...I feel like my whole life is a juggling of impossible logistics. (stepdad won't allow dss to take his bike back to their house because we bought it, but he uses it for school, so tomorrow he can't get to school. In the end we agreed he would cycle and tell SD that I said he had to. I gave him the bus fare too in case he didn't feel he could - but he can bus into school from us but not from us to his mum's as she lives further away and in a different direction).
Yes, thankless! I just try to hope he sees me like a sensible aunt or something.