For now you need to start saying "no", I am busy. I am past the point you are in the breakup/separation as our divorce will be final in a few months and it was necessary for me to stop being stepped on and relied upon as I am not her husband anymore. We both live in the same house but I am having ot move out shortly hopefully I would recommend you do the same for now as it will help you mentally
You need time to heal and be away from her. It's so hard to heal and bury the resentment when you are together and going to have to co parent....I feel your pain. Try to separate the "kids" tasks and being there for them and doing things for her.
Do your best in keeping true to yourself which seems like you are a great guy willing to help her out but don't take being a doormat and being used. It's hard....no doubt
_________________________ Me-48 Spouse-WAW 52 Married for 10 years D7 ILYBNILWY 7/15 Suspect EA/PA 12/15 No confirmation/denial She files 1/2016 Working towards the Big D ...still in progress....