"Chief Cook and Bottle Washer" from The Rink is great for self-sacrifice with a defiant twist at the end.
"You Should Be Loved" from Side Show.
"I'd Give My Life For You" from Miss Saigon
Lucy and Kendra's section of "Getting Ready" from 13
"To Build a Home" and "Almost Real" from Bridges
"Anything But Lonely" from Aspects of Love is an interesting option. On paper the lyrics seem to be about being resilient and strong, but the subtext is that she is sacrificing all her pride begging Alex to stay that it feels like it fits what you're looking for.
Marie: Don't be in such a hurry about that pretty little chippy in Frisco.
Tony: Eh, she's a no chip!