Oh Maz sweetheart, sending you loads of hugs
I am a firm believer that we aren't sent any challenges in life that we can't succeed at. Sure it may seem like an uphill battle at the moment and over the last few years you have been thrown some real doosies but I know that you have faced every one with a strength of character that I can only dream of having.
He doesn't hate you, you are his Mum and noone can ever replace that and deep down he knows that, he just hates the situation that he finds himself in and we always lash out at the ones we love the most.
And you have NOT failed him as a mother. You have done the very best that you can possibly do and continue to do it every day because you are an amazing woman and mother to all your kids.
Now my dear, do something for me, tonight once W is asleep and the household is quiet just go and stand in the doorway of his room and watch him sleep for a moment. And remind yourself that he does have wonderful peaceful times and that he does love you just as much as you love him and that you have the strength to fight for everything that he needs. Remind yourself that you were chosen for this special role because you were the best girl for the job.