how often should a couple have sex? and is it too much to ask for her to come onto you?

Samuel

this is my first time writing on this so please bare with me. my wife and i probably have sex once or twice a month, and it drive me up the wall. on top of me always being the one to initiate everything. we've talked and talked about it for years now and it'll be ok after we talk about it but give it a week or so and we're right back to square one. advice needed please.