I'm Dr. Jackie, an interpersonal communication researcher/professor and relationship expert. First, congrats on accomplishing so much in your life! And you seem very driven to continue on--that is terrific! Second, I'm so sorry to hear how difficult this marriage has been. You don't say anything that I can tell with regard to how you two met or how he was when you dated or what made you decide to marry him. So I am wondering if he was Dr. Jeckyl the entire time you dated, and I'm guessing it was a very short courtship. Mr. Hyde couldn't possibly hide for long.
It sounds like it is the typical "Run until I Catch You Game." That is, like you have indicated, when he senses you are going away or physically and emotionally are distanced from him, he will metaphorically run hard to try to win you back. Of course, he has to be sweet and nice to win you back. Once he "has" you, he doesn't have to "try anymore" because you are there. And you are absolutely right--the cycle continues and continues.
It's very sad, but this is not uncommon, at least to some degree. In many relationships, once one party "has" the other, albeit it an engagement, marriage, moving in, or some other more "permanent" establishment in the relationship, often the person who had to try harder initially to "win the other person over" feels like they can finally "relax." Unfortunately, "relaxing" in that person's mind can be twisted in that they give up all strategies of "winning the other person over," not even understanding or realizing that one needs to actually employ the same strategies to MAINTAIN the relationship.
I can give you a bibliography of references on relationship maintenance since I was blessed to have some of the top relationship scholars in the field actually teach my Ph.D. classes. Or if you would prefer to talk on the phone or Skype, I'll send you that information once I am finished here.
But for now, I'm not seeing a direct question, but I'm guessing you want some suggestions or even recommendations on what to do. If you really want to try to save your marriage, then he needs to recognize what he is doing and fix it. There is about a 1% chance statistically of him doing this on his own. Almost always change occurs through an external force, such as a near death experience, a tragedy, and/or some type of intervention. Counseling/therapy can be this intervention. But he has to acknowledge that he has a problem and secondly be willing to do something about it. And being willing means not merely saying he will change--how many dieters have said that? But until they pay for/sign up for a plan, that change never happens. It is the same with relationship change. A trained therapist/counselor can help but only if he sees he has a problem and want to change.
I hope this has been helpful. Again, I will send you my contact information should you decide that you would like to go that route. And please let me know what you think or if any of my assumptions were wrong.
Take good care,
To answer the second question, I'm sorry I missed the fact that you said clearly that you want out. Since that seems to be the case, I don't think marriage counseling is necessary. Like you already mentioned, getting yourself healthy and focused on what you really want from a relationship is what I recommend. And of course, this would be you only. To go back to the first question, this is more difficult to answer without really having sat down and talked with your husband let alone you. So I would hate to assign a false cause and effect evaluation on such a brief interaction between us. I think his back and forth, running til he catches you then turning into Mr. Hyde, you running away, then him turning nice, cycle repeat, etc. certainly has affected you negatively. I don't think that you would be human if you were NOT affected. But also like you indicated, there may be events in your past that have had such an impact on your that you have a need to act quickly or impulsively. I don't know if "impulsively" is correct, but "quickly" for sure. There may be insecurities caused by someone significant in your life who deeply hurt you and so now you have this "need" to "hang on" to someone who seems to really love you because you have this need to "keep him" before he leaves?
These last few thoughts are all educated guesses or hypotheses, and again, I think you may be able to answer #1 as you work with a therapist/counselor face-to-face and explore these issues in depth with you.
I hope that helps. I'm willing to talk on the phone or Skype if you think that would be helpful.