@Jennifer Petrillo I had the exact same problem. I used the rustoleum tile reglaze kit. It's really hard to find, nobody keeps more than a can or two in stock. Even amazon took 1-2 weeks to get it to me. It looks REALLY good. The house kept its original "feel" but also looks clean and updated. I hate when people rip the old stuff out and put in drywall and slate tile in a 1960's ranch style house. It just loses some of the charm.
My biggest advice is a) get a professional to do it b) follow the instructions line by line c) make sure and let it dry and put multiple coats. I think we used 7 cans of it total on those two bathrooms. We did the tub and walls. It's also really strong so make sure no others are working in the house.
I cannot attest to how long it'll last but there are some good reviews on Amazon that it seems to hold up.
Rust-Oleum 7860519 Tub And Tile Refinishing 2-Part Kit, White https://www.amazon.com/dp/B000PTSBKW/ref=cm_sw_r_cp_api_wug5ybHDV4V1K