Try to hang on until he leaves for his assignment. Then you will have made it to the eye of the storm. Take the 6 months to assess your situation, how you feel, how your kids feel and how your husband feels.
There is the temptation to just end the suffering by divorcing. It might seem appealing but you may switch one set of problems for another. The loneliness is one of my greatest challenges. It must be very difficult for you as well. You will have more time to spend with friends when you husband goes. You could be lonely and facing reality. Stay focused on the here and now. Tomorrow wil come and you can deal with it then.
I would not cling to timelines to force a decision. You have to weigh the evidence each day and decide if the pain of staying is greater then the pain of leaving. That is a big question and the answer should not be forced. You are the guardian of your precious children and they are relying on you to make right choice for them. This is a big deal.
Use the 6 months to rest, relax and regroup. Be well
