Marrried 13 years, Any advice appreciated. Thank you so much?

Please help. I have been married for 13 years. We have 2 girls ages 7 & 8. I consider myself a good looking woman. This is the issue: My husband took a job overseas in the UAE. He travels home every 4-8 weeks to spend 2 weeks with us. When he arrives his attention goes immediately to the girls, which I am glad for, but at the same time, I've missed having a husband all that time. I was diagnosed with Fibromyalgia about 2 years ago, but have been living with the symptoms for 7 years now. My husband is a physical therapist and will only touch me to work on me if I ask -- so if I don't he rarely offers even knowing how much pain I am in. He just tells me to get out and exercise. Ok, back to when he gets home. He never initiates -- I have to be the one. If I don't ask, he doesn't offer -- it has been two weeks now and he is on his way back to the UAE and has still not touched me. I feel very sad and displaced. I feel extremely unloved. When I ask about an affair he gets angry and says he would never do that to the girls, or me. He is hard to have a conversation with if he has a diference of opinion with me -- he can get very biting and mean in his responses. He tells me when he is home to go rest, as I have very little when he is gone, but sooner or later throws it in my face that all I do is lay down. I try so hard to be active and do everything I can while he is home because I am affraid of upsetting him. I am just at a loss and very unhappy. I don't know what to do. There is no emotional or physical intimacy between us and I find myself begging for our time together. I only have 2 weeks with him, and I wish he wanted to be with me, spend time with me, as much as I do. What do I do? Please forgive any typos or rambling -- but I have to write this without him seeing it. Please give me some advice and help me understand what is going through his mind. Oh, and so you know, we all did move over seas with him for approx. 7 months, but the government did not allow the medication I needed so my husband decided moving us girls back home was in everyone's best interest. I feel like a failure and let him down. I tried so hard to live with my pain, but it was debilitating. Please, Please help me. I know, if anyone, you can. Thank you so much.