A “rust converter” like Rustex and Enrust or a phosphorizing agent like Ospho would be the best option to extend out the life of your rack.
Scrape off the loose paint and any rust flakes , and apply liberally to any exposed metal. Wait 12-24 hours, then prime and paint. I’d use the brush-on Rustoleum, over a spray paint, because you can get more complete coverage and a thicker layer with fewer coats.
Like above, the best you can do is slow it down and buys some more time. I don’t think your rack is in danger of failing within the next couple months, but I’d Enrust it, and keep an eye on it until you get home and can properly overhaul it.