Hello, I am Rafael. Thanks for asking your question - I'm here to support you. (Information posted here is not private or confidential but public).
I am sorry to know about this sad and frustrating situation in your life.
Your message, while brief, shows how important it is for you to be close to your sons an grandchildren, because of how much you care about them and the attachment you share. These feelings by themselves use to be healthy and really fulfilling, but when satisfying a longing and need like this is conflicted with other interests like your marriage and your husband's decision to stay where you are currently located, thing become truly tough.
You said you appear to be willing to rebuild your life leaving behind your husband in order to fulfill this need you have, right?
If that's the case, such an important decision should be based on a careful assessment of your priorities in life, the pros and cons of such radical change, and what you would have to afford from it.
If your sons want you there and offer their material and emotional support for that to become a reality, and you truly feel that this is much more important in your life than to stay with your husband, then it would make sense for you to work on this transition. Each person is unique, some do value their marriages more than anything once their children become adults, while others feel the need to stay close to them and their families. You just need to be totally truthful with yourself in order to do what you feel and know would best meet your core needs and expectations in life now and in the long run.
You're very welcome. Thank you for your trust. Please take your time to carefully assess this situation, to dialogue with your sons and husband about it, for you to be able to make a sound decision based on what truly matters the most for you, being realistic and truthful at the same time.
Work on this process being unconditionally gentle, understanding, patient, compassionate and supportive with yourself, in this way you would be able to cope, choose what truly works for you and grow from this challenging experience.
Then he has already decided what he wants and will do. The same way, you have the right and need to choose what is the best for you.
Then each of you know your priorities. Now it is about taking consistent actions in order to fulfill them, with the right means and support.
You're welcome. I support you and hope you further fulfillment and well-being during this challenging but necessary and worthy process.