The confusion comes because you are thinking of probability waves, which is what the interference pattern from elementary particles through the double slit experiment are, as if they are classical waves.
Current day physics accepts that the fundamental framework of nature is quantum mechanical. Classical mechanics, classical electromagnetism are emergent theories from the quantum mechanical foundations, in an analogous way that thermodynamics is an emergent theory on the substratum of statistical mechanics.
The electromagnetic wave is a special case because the classical wave as given by Maxwell's equations emerges from the coherent synergy of a huge number of photons, i.e. elementary particles. If one is theoretically inclined here is a link which explains how photons build up the electromagnetic wave.
The photon's energy is given as E=h*nu where h is Planck's constant and nu the same frequency that manifests in the emergent from zillions of photons classical wave. The double slit interference appears even for a single photon at a time, and the pattern gives a probability distribution, the probability of finding the photon at an (x.y) on the screen.
The same is true for single electron interference patterns. It is the probability which is given by the square of the quantum mechanical wavefunction that manifests in the pattern. The electrons pass one at a time and are deflected according to that probability. There is no matter or energy wave in the quantum mechanical framework. Just a probability of detection.
