First, working with less-than-ideal images is instructive. You learn the limits of the camera, the film and darkroom printing. Understanding this makes it easier for you to make a better image next time. Basically, we learn from our mistakes.
Second, negative that we think are trash on one day can be made into good pictures on another day, in other ways.
Many years ago, I took a photo on the subway platform at Kendall Station in Boston (Cambridge) Mass.
It was dark. The shutter speed was low. The aperture was wide open. The picture was dark and blurry. When I took the photo, I gave it a quick look and thought, "Trash."
Twenty years later, I was going through my old negatives and I happened to look at this image again. It caught my eye so I scanned it and looked at it on the computer screen.
Turns out... If I changed the way I look at the picture, I was able to make something out of it! If I had trashed that picture, I never would have had the opportunity to make a good image out of it.
So, the way I see it, go ahead and work on the image you have. See what you can do with it. Maybe you'll make something good out of it. Maybe you won't but you will have learned something in the process. Then, put it in a notebook and file it away. Maybe, years from now, you'll look at that picture with a fresh eye and see something you missed before.