Hi! I'll be glad to be of help with this issue.
I can imagine how worrisome this situation must be for you. You are clearly a loving and caring parent and this situation brings on a lot of concerns for your son.
We certainly can't and shouldn't minimize the feelings of sorrow you have for his feeling so sad and hurt about the breakup. These are natural feelings. But you are sensing that he is taking this further than the natural sadness that would happen in such a situation. You are sensing he has become depressed or at least, he has lost his emotional equilibrium, because of this breakup. And he's acting from his emotional disoriented state. You are right, this is not a good situation.
He is an adult, however, and in my experience, it is very difficult to dissuade a young adult man to step back and assess his actions from a more objective point of view. This, though, is what you would want to be your first effort. To tell him that you love him and that you are so very sad for him and that you can see how distraught he is by the breakup. And that you want him to make sure he recognizes that his life is still full of possibilities without making such dramatic changes. That in life, making dramatic changes from intense hurt and pain is often not a good idea. That we don't have the objective viewpoint when we're so hurt to know if we really are making a good decision.
You might then see if he would be receptive to seek counseling for a few sessions to discuss with an objective person the situation and his options and his reasons for making his decisions, etc. Often, it's easier for adult children to accept this suggestion than to accept parents' direct advice. Especially when they're suffering and depressed, accepting advice from those they love is not easy.
You may not be able to dissuade him. That is a possibility. And if so, I don't want you to give up, to feel as though the situation is lost. Your support and contact with him is important to him as well as you. Today, there is Skype available. It is truly remarkable. I use Skype for therapy, for example, with people who find it more useful to them than going to a psychologists' office in person for some reason or another such as living in other countries. Skype can keep you connected to him and him to you.
And this can help you help him even if you can't get the best results. That's an important thing I want you to keep in mind: even if he can't be dissuaded from this move, you still can and need to stay connected and today those means are readily available to you.
Okay, I wish you the very best!
My goal is for you to feel like you've gotten Great Service from me and the site. If we need to continue the discussion for that to happen, then please feel free to reply and we'll continue working on this. If the answer has given you the help you need, please remember to give a rating of 5 (Great Service) or 4 (Informative and helpful), or even 3 (Got the job done) button. This will make sure that I am credited for the answer and you are not charged anything more than the deposit you already made by pressing any of these buttons. Bonuses are always appreciated! If I can be of further help with any issue now or in the future, just put "For Dr. Mark" in the front of your new question, and I'll be the one to answer it. All the best, XXXXX XXXXX