A Reader responds:
Definitely, empty threats have not worked, on either end. She is asking for her boyfriend to commit, but on the reverse end of that, she is also not sticking to her guns about what she wants and what's right for her.
By your own example, you have taught your boyfriend what to expect and how to treat you. Before trying to change him, you need to change yourself.
Make your decisions based on what's best for you -- if you want to be married to HIM, then tell him it's time to move forward or it's time to end it. But you have to mean it -- you have to follow through with it. If you don't, you are no different from the man who changes for two months and then reverts to old patterns. You are also reverting to old patterns -- if you change yourself, then things around you will change.
A lot of people assume that things will be happier if "he changes" -- forget that. You can't expect HIM to change because YOU are unhappy -- you have to make the changes within yourself first. Figure out for yourself what makes you happy first. If he (AS IS) truly is one of the things that you are happy with in your life and want to move forward on, tell him: "This is what I want, this is what I need; can you meet my needs?"
If he can't, respect that and move on. And if he says he can, ask for more than just his word. Ask for counseling for the two of you, ask for a firm commitment. But if you just jump into the same pattern again, nothing is going to change. Instead of expecting him to be different, SHOW him that you can be different and that will help teach him how.