Getting very frustrated and tired!!

After 2 years of my DH having very little sexual drive and now TTC with this issue I'm losing it!! I'm frustrated because it's close to impossible to get him to BD on my most fertile days! Im sexual frustrated because im expected to some how instantly be turned on and I have to do all the work to just simply get him aroused and stay aroused so he can finish!!! I'm so fed up!!! I'm sooo frustrated!!!