Hi Lolita, you say "I just wanted to know the best way to deal with their moodiness...and how to get him to open up more...not leave his girlfriend....just be more emotionally available to me....." Well, any person cannot be invested emotionally the same in two people, if it is a romantic relationship. So, while you say that you do not want him to leave his girlfriend that means exactly that, that he cannot be more emotionally available, because he is not really available, he really can't be. What you will get with him is just encounters every once in a while (whether through text or in person), and even though they are important to you and maybe to him too, that's all that they can be while you are both attach to other people. He will probably not be able to open up more, nor should you if you are giving a real chance to your relationship with your husband. I was married to a cancer for 10 years, together for 12. I had another relationship with a cancer man after my divorce. No amount of begging will make them talk when they do not want to talk, you'll just push him away. They do better with laughter and simple daily things than complicated analysis. While they might be doing it on their own (thinking, analyzing) that doesn't mean they necessarily want to share. They need to go into their shell pretty often and they get along with people who understand that. It is not personal, it is just how they are.
I hope that you are feeling better about yourself and that you see things more clearly.