Without seeing a clear picture of the other side of your fence or knowing if your property is on the other side of your fence. I will tell you a few ways for erosion control.
First is roots. But you have to preserve he soil in order to establish roots.
One way I have done this... Is to pound stakes or branch sticks deep into the ground and fasten a netting over the top. The netting works just like weed barrier only it hold the soil and plants can grow through and around it.
If you could get me a better picture of the area you are talking about I can help you more. Both sides of fence...,
Where the soil is washing out to...
That sort of thing.
