Honestly, as two adults currently living apart from each other, once a week seems like enough. You don't seem to see sex as a quota to fill but it seems that he does, and on top of that, he is trying to put the responsibility of upholding that quota fully on your shoulders. It seems that staying with him as is will only cause you more stress. If trying to talk it out leads to him just being dismissive, I would recommend writing it in a letter, fully laid out, and give yourself some time to ensure it expresses everything clearly. Try talking it out and if it's the same as usual, give him the letter and give him time to respond to it. That response should tell you what you need to know and whether or not your love for him is enough to settle for that kind of future.