I?m not very articulate and it?s taken me ages to type this so things may have moved on now but what I?m hearing you saying is that you have a comfortable life with your H but it?s all fake. You sound very unhappy. You also sound preoccupied by what everyone else will think, as well as worrying about the practicalities of splitting up.
?maybe just because I'm after something that doesn't exist anyway? I think we all deserve to be treated with respect and kindness. No one deserves to have their H muttering things under their breath about us unkindly. That is awful and not normal.
?would I be doing it purely because I think I'd have a relationship one day which might be better? Possibly but everybody ought to have feel loved. There?s nothing wrong with that.
If you cannot be civil to each other that is very harmful for your DCs as you recognise 
?I can't bare him even touching me now. When he brushes past me I want to scream.? This makes me so sad to read. I think you?d be doing yourself a disservice to remain together if you feel like this. Children aren?t daft and no matter how you behave on the outside they can see beneath it. I also do not think what you have is normal for some. In this day and age you do not need to ?put up and shut up? as someone else said it?s not 1911. A sexless unhappy marriage?
Nobody warrants that.
?Give me some strength to at least pretend I'm happy in front of the children? I am sending you strength but actually to leave this situation.
You will be a better mother and feel better within yourself too when you?re no longer in this situation. It is possible once the initial turbulence of separating is over to have a good co parenting relationship. My ExH and I now co parent very well and the children are settled and happy. I felt very guilty for a time at the children growing up in a broken home (for want of a better word) but I am happy and so are they now. I also surprised myself with how I learnt to manage, learnt to do DIY and a number of other things. It is a very scary step to take and I was afraid of what others would think and how I would manage but you just do. Especially if you have good friends to call on. If you go and see a solicitor and start to arm yourself with information you may find you feel calmer. It is natural to feel like your mind is a washing machine over a big step like this but I hope you can post on here to help clear your head in the weeks ahead.
It is always worth considering marriage counseling before divorce and I think mediation is now compulsory in the divorce process, but I could be wrong. But please do not stay together through fear of what others may think.
What is the most important thing out of what you said?