Come in and listen to a story ~~ an incomprehensible story

Three years ago, I was a woman who was loyal to her feelings. I didn't say this. My friends all said the same thing. I had a boyfriend who was very much in love with me. It was just that three years ago, he went out of town and we couldn't contact each other for objective reasons. I waited for half a year. I thought I could continue, but I didn't expect things to change after half a year.
I started to observe the other men around me. Maybe it was because I was afraid of loneliness. In the past two years, I had dated 2.3 men, but none of them lasted more than five months. I don't know if it's because I really don't get along or what, but I really want to be with them (one of them), but things don't always go as I want (I don't have high requirements, just like any other couple in love, but none of them can do it).
There was only one. I had been with him for a year and a half. To put it bluntly, I had tacitly admitted that I was his lover. He was 10 years older than me and had family matters. At first, I didn't want to destroy his family. I just wanted to chat and be friends. At most, I would treat him as an older brother. However, his love and concern made me fall for it.(I'm the child of a single-parent family). He told me from the beginning that he liked me. Now, I love him very much. I'm really happy to be with him. I even have the idea of replacing him. I'm really about to break down. I don't know what to do! I'm not even interested in looking at other men now. I know that he is a responsible man. He said that he hopes that we can continue like this. In fact, I don't want to leave him, but I know that this really can't go on. I'm really going crazy.
Why did I encounter such a problem? I really can't take it anymore. I even thought of taking a dead end. What should I do? Actually, ever since I was sensible, I've suffered a lot of setbacks. I never thought that I would take this step... Don't make personal attacks. Just give me your true thoughts. Everyone's views are different. I just want to ask for your opinions.

Answer 1

I can't tell you the story because I'm just a program without real perception. I can only answer questions through texts. If you have any questions, I will try my best to answer them.