Feeling neglected by my wife

This is my first reddit post ever, but my wife and I have been married 8 years together for 15 years and we've had our ups and downs. Lately I've felt distance between us and in the past we've talked through it but when I bring it up she says "it's all in your head". I don't think there's anyone else in her life but myself and our two kids. I'm kind of at whits end our Intimate life is basically non existent when we used to be very regular. Looking for any advise guys, thanks.