Just an observation (but I will call it a very astute observation because I've been where you are) but you put a lot of focus on your ex and how you feel lonely without him. It's like your brain has so much space for thoughts (this is just an analogy so bear with me on this picture) and you have used 95% of your brain on your ex and why you are not over him. This is how you are directing your thinking.
If you want to stop thinking about your ex, well fairly simple, it means you have to stop thinking about your ex. But writing posts and talking about it is only activating it. I wouldn't be surprised if this thread is making you miss him more, because you keep on talking about it.
Following my picture analogy, you need to focus your thoughts on other things than your ex and how you miss him. It would be better to just daydream about another man, instead of complaining about the last one that dumped you, because when you daydream about someone that treats you well, you feel better and give off better vibes, than giving your attention to the belief that you are alone, because you were dumped.
This is a trick of the mind on how you choose to perceive reality.
But the fundamental rule to get over a breakup, and this has been said quite a bit on this thread, you have to move on, and think about something else. And it will eventually mean, closing this thread, because this thread is making you focus more on how much you miss him. The more you talk about your ex, then the more you continue to talk about it, and people will eventually get tired of hearing the same story from you.
However you have to do this in little 'baby' steps, thought by thought, feeling by feeling. You have been given excellent advice to distract yourself with your ex, like education, classes, a job, or other friends. Possibly even another boyfriend, but remember, wherever you left your last relationship (and it seems this feeling of dependence is active in your experience) it will manifest in your next relationship, until you deal with it now.
And the way to deal with it is to manage how you react to the trigger of being left alone. Everyone has different responses to breakups; some just move on after a few weeks of bitching, others continue to struggle for years. It all varies on the person and their past history on how they view relationships.
Some people grew up in families where they felt secure in relationships so they don't feel as needy when they encounter a romantic partner, and when they break up, they have that sense of security intact so they can move on. Others however may not be gifted with a good past history with a family that gave them a feeling of security, but regardless, it's how you react to the breakup that determines how you live your experience.
As I perused this thread, I've noticed there is a lot of glorification of your ex, from the feeling of powerlessness. Meaning he is all that, and not that you've lost him, you can't have that.
To be short and blunt, you ex is not your ticket to being whole. That is a misconception on your part, instead he is just a representation on how you react to your life experience. In your belief, you feel you need someone to validate you. And when you loose that someone, you loose your sense of identity.
If you listen to a lot of romantic songs, you'll notice many breakups go through a period of anger. In fact, that's normal for survival, but you'll also notice, that those who go through anger to clean up their feelings about their ex, eventually get through it where their anger moved to feelings of hopefullness, and then eventually to appreciation for where they are right now.
It seems to me there is no anger about being dumped from you. Instead it's just this feeling of powerlessness that your ex dumped you. If your feeling powerlessness, the next best feeling is anger and revenge. And I would recommend you stay there until you can get to higher feeling of frustration and hope.
I've been where you are now. And over a period of time, I got angry, bitched, but only to the point to feel better. I never called my ex and explained my reasons for my bitching, and he never had to hear me whine. As much as it hurt to say it then, he has his own life, and I had to respect where he was. And he has a right to live his life without me.
But when I went through the anger and reached for higher feelings, like revenge, I eventually moved to frustration and to hope. I kept on reaching for better feeling thoughts and in time, I cleaned out my emotions about how I viewed my relationship with other men. And I can tell you now, I don't feel as needy as I once did in a relationship, and I can thank my ex for forcing me to face that part of my neediness which he activated when we separated.
Your work is not to change your ex, but to change your relationship with you on how you choose to view life with how you think. And you can do this by changing the direction of how you think, by finding ways to feel better about your ex.