Being the assistant

Man I'm hacked off!
I don't mind being an assistant coach, and just doing the odd training session as and when I'm needed.
I also don't mind being an assistant coach who just takes the 2nds or the 3rds and puts them through their paces.
But if you give me a team, and tell them they're mine, and then I have to sort out their faff of a training schedule, and take time out of going to the gym, and take time off work to do technical sessions in the middle of the day then you do not email me just as I'm going to bed to tell me that actually you're going to coach them tomorrow and I'm not needed.
It pisses me off.
It messes up my day (e.g. if I haven't bothered to wash my gym kit as I know I can't go to the gym as I'll be with them).
It completely undermines me as a coach.
And it messes with my training program!