She wants marriage, I don’t

I am a 45-year old man and have been having an affair with a married woman for two years. Over the past month or so, she has begun to talk about marriage. She wants to divorce her husband and be with me. I love her a lot but am not interested in marrying again. My wife and I have an estranged relationship, but we have to stay together for financial reasons. How do I convince my lover to end this relationship, or find a way of keeping things the same? I know this is a complicated situation, but there is no solution. If my wife finds out about the affair, it won’t change anything because we don’t love each other, but I don’t know how she may react to damage me in other ways. What should I do?
I’m not sure what exactly you are asking for, because it sounds as if you want a solution to committing adultery without any trouble. The facts don’t change. You are married, as is the person you are having an affair with. The current situation is not tenable not only because it is illegal, but because there is nothing either of you can do about this until you end your respective relationships with other people and think about what you want to do next.

Is it okay for two people to marry after just six months of dating? My girlfriend and I are considering it, but I am not entirely sure because even though I love her, I think we should get to know each other a little better after the honeymoon period has ended. She thinks I am being a pessimist. What is the right amount of time before we should take this step?
You and your girlfriend alone know the answer to that question. However, given that what you are considering is a commitment to live together for the rest of your lives, I would suggest you take as long as you both need to, until you feel comfortable.