Sounds like it's all piling up on you mate , I know the feeling one more straw will break the donkeys back ,my daughter is pretty much the same we do everything for her then when we ask a small favour we get excuses partly my partners fault for doing everything for them because of her own upbringing .
It's not easy but you need to break it down and talkle one problem at a time .
The egr vavle probably needs taking off and cleaning out they get clogged up with soot and oil most cars it's not a huge job , I took mine off and threw it away and blanked the hole off .
You are not alone in feeling overwhelmed it seems the way lots of people are feeling these days , hang in there chap .
Take care