My DP and I have been living together for 6mths (together 3yrs) he has 2 children SD 13yrs and SS 9yrs, his ex is shall we say difficult psycho and does not allow the children to stay at our house or me to spend any time with them and has a history of with holding contact if things dont go her way, she has also disappeared with them for several months (in her words "just because she can") so for this reason we have so far gone along with it, which was fine when we werent living together as they live 170 miles away so he has them 1 weekend a month, all half term holidays and half of summer holidays, but now we are living together I am finding it increasingly hard that he has to leave our home and stay at his parents with them.
Christmas has broken me, which I realise sounds dramatic but I dont know how else to describe it, he offered her christmas and boxing day up until the 29th when he would collect them and have them until the 2nd, she wasnt happy with this and said she would bring them to him on boxing day and he could take them back on the 29th, then my DP`s mum told him that he couldnt stay at her house on boxing day as she felt he should be with me so he had to tell the ex that unless she agreed to them staying at our house he couldnt have them, needless to say she flipped and said no, so then it was decided he would collect them on the 28th and take them back on the 1st, by this point I had changed plans with friends so many times I had missed out on booking any of the things they had planned (you would think I would have learnt by now not to change plans) and have had the week off of work so have literally been sat at home on my own which has given me too much time to think.
I feel like everyone else has taken control of my life, I can accept - but not like -my DP and ex having some control as its their children at the center of it but I have struggled greatly to be ok with my DP`s mum (who I get on with brilliantly) making the decision that he should be with me on boxing day therefore changing the plans yet again, I was happy with the first plans and the second ones but was and am not happy with the situation that has now left me feeling out of control and very much alone for most of the christmas break.
My DP swears that he is going to put his foot down and insists things will change, I agreed to not do anything until after christmas as didnt want to ruin christmas for the children in any way but right now all I want to do is pack my bags and leave, im fed up of being left for weeks at a time on my own, im fed up changing plans, im fed up of everything being her way and im fed up of my DP letting her get away with it (I know he is in a difficult position), im fed up of feeling resentful and guilty and sad all the time and im fed up of being told "you knew what you were getting into" and im fed up of being fed up 
thank you if you got this far, feel free to tell me to stop whining