I am married but still in love with my ex
You have never settled down. You loved a guy in high school and he did not show enough interest in you, so both of you broke up. You shouldn't condemn yourself for what happened.
However, what you might be calling love is not love at all. Perhaps it is lust. And what is lust? Lust is having a very strong sexual desire for someone. That feeling is temporary.
After one succeeds in getting that sexual desire satisfied, one wishes to move on and one does not care how the other feels.
When you got married to your husband, you really didn't love him. You just wanted a man in your life, and you got one. But the desire to be with him forever until death separates the both of you was not there and is still not there.
You would rather be with the one who spoke about his ex all the time and with whom you couldn't deal with his chatting about her.
You are always thinking about him although you are married. You are an unhappy woman. I would say to you that you need to get back to basics.
What is it that brought your husband and you together? Can you find it? Is it lost? Can it be found? Very often when couples don't get along, it is because a number of things have gone bad. Perhaps you don't spend enough time with each other, and the little things you used to do together and you enjoyed, you don't do anymore.
Perhaps the sex is rather boring. You need to spice up your marriage. Spice up the sex. Your big problem is that this man whose ex was in the way of the friendship between the both of you is still around. The desire to be with him is haunting you.
If you were wise, you would put him behind you and do your very best to work with your husband and to strengthen your marriage. If you love your husband and love yourself, you would work on your marriage.
You will always be unhappy if you are always thinking about another man and ignoring your husband. Only you can help yourself, so deal with yourself.
No one is to be blamed but you. You said that your husband is a good man. Why wouldn't you want a good man?