Oh, Hyper, sorry you are having such a tough time. I think it's extremely difficult to come to terms with things not being right. When King Alcohol is in charge and we are either pissed/planning to get pissed/struggling with a hangover etc - there isn't much time to deal with (or frankly notice) any of that 'big' stuff.
I think it's sort of 'growing up'. So we have to face - and even worse DEAL WITH (at some stage) those tough things/decisions. Take responsibility etc. All that stuff that no one wants to do, really.
I find having kids underfoot all the time can be very hard. Maybe that sounds dreadful, but just how I am. Love them to bits, but when I am trying to get anything done/think/work/frankly just unload sodding dishwasher - it is 100x harder than when I am on my own and I can get resentful about it.
Don't remotely feel in a position to offer any advice, but maybe things will be easier after half term. If you have some space and peace perhaps you can have a really good think about how things are with DH and whether it's a case of working through stuff - or whether you just want out.
I find writing a gratitude list from time to time really helpful. Sounds sort of silly, but actually putting pen to paper can be a good discipline. For me, anyway. Any old stuff can go on it - from being happy the sun is shining, to having enjoyed nice coffee earlier, to having good health, lovely children, roof over head, anything really. When you start, you realise the list can get really long. I have heard people with what most people would think are really shitty lives come up with an amazing catalogue of things they are grateful for and it puts stuff in perspective and makes me feel less sorry for myself.
Which isn't to suggest things are all perfect, but can just help to right size problems so they are one thing in a sea of better things if that makes any sense.
Right - should get off MN and try to update CV. Argh! Allowing kids to play on Temple Run in slobby mummy fashion!