Of course you can divorce and get a new life that’s much better at 58! I won’t say “start again” bc that implies trying to wind the clock back, which isn’t possible and creates a feeling of being in the wrong time and place, imo.
What you CAN do is take all your life experience and wisdom and use it to move into your next stage of life. It’s a real pity about such a long marriage, but some just don’t make it, through no fault of our own. Some of us have spouses that turned out to be a dreadful disappointment. What is the worst possible outcome, imo, is that you waste further years in this marriage and wake up at seventy, with the same old problems, wondering how much better life might be if you’d got out while still in your fifties.
Personally I think it’s better to be single forever than with someone who betrays you.
Also, there is a growing number of LATs. People who live apart together. That is, committed couples who don’t live together.
You have a ton of options for how you want your next fifty years to be (let’s be optimistic!) and you don’t have to settle for what sounds like a half-life. There are so many things to do in the world these days, so many hobbies and people to meet and places to go. If you’re lucky, maybe you could salvage a friendship out of it with your husband.
In summary, NO WAY is 58 too old to have a change of lifestyle!