Good morning all!
Welcome to the thread Weddinggate and MrsPMT! Sorry you are going through such tough times 
I'm nodding madly again because we've had a period of attempted school refusal (thankfully now resolved) , the being up at night (still happens sporadically), reluctance to shower (despite my best efforts, smelt of horse, dog and grime for tween years but thankfully transformed literallybovernight the day she turned 14 and now she hogs the bathroom for hours) and over-use of phone (still ongoing but improving ) and eating too much sugary rubbish (ongoing) and deception over whereabouts (ditto) - and I know how deeply irritating and frustrating each and every one of those issues is to handle! It's the sense of exasperated helplessness that gets to you, and the overwhelming feeling of "FFS life is hard and complicated enough battling every day to try and make sure you are safe, happy, healthy, fed well, well educated etc etc without you constantly doing silly unnecessary stuff to self sabotage! " (Patience not my strong point.
). And then when it all goes on for too long the feeling of "FFS, if you are not going to put one ounce of effort in to making sensible choices then why the f should I bust a gut over it all, just ber off and suffer the consequences!". OK so I have never said that last bit out loud but ... .
It all just a phase. It's all just a phase. Rinse and repeat!
Exam season here - very very up and down - get snapped and ranted at for such "controversial" statements such as "please pass the water jug".
Yet am "treated" to long "emotes" (YY to the "neediness" !) late at night on life, the universe and everything (usually as I am just going to sleep ) and am supposed to hang on to every word even though I've been on the end of such hatred and spite and vitriol only a couple of hours before. (Yes I know I sound horribly grudging but it does grate.) I feel like Gandalf - walking on eggshells and tense - because of the "on/off switch" nature of the moods 
As Billy and Tickling said, as a "facilitator" I no longer have an identity in my own right (in dd's eyes anyway) and this lies at the crux of my ongoing battle with her - I am "less valid" than DH who provides financially. I think she'd be quite happy if I left and she and dh could live happily ever after ... . 
Machinebee your DH sounds fab!
. Sorry about family tensions and sympathies re: lack of respect (same here). I don't think your dd should be dictating the terms when you are kind enough to help her out with childcare.
Anotherlover hope your ds is ok bless him. Despite all the frustrations listed above, you can't help feeling for them when they go through such agonies of self-esteem.
Last but not least McMen oh your poor dd. That is awful! Was the teacher able to help? Hope the school are cracking down on the nastiness (and the homophobia). Those comments are most likely coming from a place of jealousy and I hope you can encourage your dd to carry on doing what she loves and is good at, despite the opinions of so-called "friends". It's funny isn't it, so many memes on Facebook and the like about "living the dream" and "being your best self despite all the hurdles" etc etc and yet in RL, the teens just don't join the dots ... .
My dd is at home a lot right now in between exams and (awful though it is to say) I am not looking forward to eight weeks of summer holidays with undiluted joy, so apologies for the rather Eeyoreish tone of this post. Just trying to survive day by day!
Keep going Po Ts! Wishing you all the patience and strength that I seem to be lacking currently! [Tiny violin plays in background.]
Seriously, hope you all survive the w/e without too much angst!
. Solidarity! ✊