It makes sense to me that the cherry varieties of tomatoes would do the best, they are in my state native plants and hardier against all pest attacks. If you can’t rotate plantings of resistant plants into your tomato garden then you will need to rest it from tomatoes and all plants that are hosts for nematodes. If you can afford to keep it fallow then pile on lots of organic material so that your garden becomes a compost pile for a couple of years. After that you should be able to try tomatoes there again for a season.
With sandy soil, if you are growing plants that do not thrive in sand it is important to build the soil which means always adding organic material that will break down there. This has the added benefit of attracting beneficial nematodes that consume the root nematodes. In order to reap the benefit of the compost organisms that help keep nematodes at bay it is important not to disrupt the life of your soil by applying synthetic fertilizers or pesticides.

Please look at the composting articles on the manuredepot blog. I write a whole lot about that, and it may help you too.
Thanks again, and best of luck in your garden.

I’m composting and will keep doing it. I’ll begin rotating, too, but I don’t have easy access to all the plants you suggest for rotation. I’ve just made a neem-based tea with garlic (for what that might be worth). But, I’d still like to try more ideas. Any suggestions are really welcome. Thanks!

Naomi I was not aiming at making gardening seem hopeless. The point I was hoping to make, and I guess I didn’t was that nemotode protection is just another good reason for composting and feeding your garden lots of organic material. Thanks for the wake up. I guess I better make a post about this.