Stopping more erosion

I have no time or money to fix the erosion problem before winter. I decide to temporarily patch the opening of the cavity with insulating foam ($14.88) to prevent water from getting inside. It took 3 cans of large gap filler to plug the openings. The massive cavity extends from the downspout on the left all the way to the garage door on the right, and seems to be at least 4 feet deep.