Dear Annie: I’m 67 years old, and I’ve been married for over 40 years. My marriage has never been particularly happy. Even in the beginning, I felt pressured to get married. We now have two adult children, one 46 and the other 37. I met a woman online, and we’ve been chatting and talking for over two years now. I really like her; she’s a little immature but seems fun to be around. She is also…