preface: I am in a marriage similar to yours from your husband's point of view.

I feel like it's more about managing expectations and effective communication than anything else.

That is wishful thinking on your part.

You didn't mention whether you are actually attracted to your husband. In fact your desire only came up once in your post. Have you (or he or both) visited r/deadbedrooms?

Is there a medical reason for your lack of desire? Psychological? Are you actually attracted to your spouse? Do you both still go on dates, give each other gifts, etc? Does your husband work out, have hobbies, spend time with friends of the same sex? Do you take time with your own sexuality, stimulate your sensory imagination and perception, appreciate the vitality and vigour of your mate? Have you been to couples therapy, read any self-help books?

You say you're at your limits. If you don't feel desire for your husband, don't force yourself to give him sex. It's insulting and deceitful.

If you've gone through everything and still feel no desire to fuck your husband except the one time of the month, there is something wrong with that, and it isn't fair to leave him in the dark that you "love him but aren't in love with him."

He deserves to be in a marriage where he is satisfied and you deserve to be in a marriage where you are satisfied too. Having sex with a man you aren't attracted to is not satisfying you anymore than a lackluster handjob and starfish sex every week (in lieu of sex only once a month) is satisfying him.

He wants to be desired ... to be wanted. You can't seem to give him that for whatever reason. It's certainly not completely your fault, but it's only fair to be honest with yourself and with him.