I'm sorry to hear you feel like this @40andtryingtoimprove . As an old gimmer in my mid 50s, who has been with the same man for around 35 years, I can't relate as I've never had a long term relationship break down, and gone ahead and split up.
We've had our ups and downs, bad times and good times. Plenty of good laughs and a lot of fun, but some problems as well. Times when I felt like leaving - but I did stay for the kids at the time. I ploughed through and stayed. I'm not saying I'm any better than anyone who leaves. I just dealt with things differently. Decided to stay.
For the last 13-14 years, me and DH have been happier than ever. I know what you mean about how it's nice having a nice cosy family unit. Being in a couple together to deal with things in life. Financial things, family things, work things, health issues, and general peaks and troughs in life, and helping and supporting the kids together etc.
Somebody said something on a thread the other day that I thought was very profound. They said 'the thing is, when you leave a relationship because of a few bad things in it, you're getting away from the bad things in that relationship. But you're also leaving the good things in it as well.' And that's true.... like the financial security, and the company, and someone to share life's mental and physical loads, to share the bills with, to go on holiday with, to socialise with, and to share your life with.
It's a really tough one, isn't it? I think unless your marriage is really severely bad, it does make you wonder if it's worth staying and trying to work through the problems.. I guess some have issues so serious that they make the marriage impossible to continue, but I do wonder if some people give up too easily, as I have known quite a number of people split up after 15-30 years together, and regret it.
As I said, there were a few times when I felt like leaving my DH between maybe 15 to 20 years ago. But now, I'm actually really glad I didn't because we're really happy now. I'm really sorry you're having a rough time and hope life gets much better for you soon.