What to do when you partner does not want sex due to Erection problems due sex

My partner and myself are in our early thirties. We have been together for almost 4 years. We have emigrated to Indonesia a year ago for my partners job. He is incredibly career driven and focused. I admire him for what he has achieved. However, he is a closed book person and does not express his feelings towards me in regard to relationship issues. Before emigrating to Indonesia we had a very active sex life. Maybe having sex 3 times a week. Healthy and very satisfying.He recently went to America on a business trip for 2 month’s. When he returned, he tried being intimate. To start with everything was great. But after 5-10 minutes into getting steamy, he went limp. We took a paused and tried again. But nothing seemed to improve his erection. This has happened now every time we have tired. It seems that he is losing confidence and we have not even tried having sex since. It is getting both of us down. Although I have a high sex drive then him as he is always mentally concerned and focused on work issues. I feel the lack of intimacy and effort is pushing us or me slowly away. He doesn’t even instigate it and he shows very little physical contact. I want to support him and help him focus on us and the issues we have as aposed to his work. But his work always seems to come first. Please could someone help me? X