i used to understand sacrifice in marriage as one person getting totally walked on and bullied.
many people think that in order not to get bullied, you have to be really strong and never give in.
but the truth is somewhere in between.
the better you get to know God, the more you realise that God loves you (it means He is never mean, never pushing you to fail and always saying something nice). to really understand what God's love is, read 1 corinthians 13, and then go to church for a year or two (sorry, it takes time to understand it!).
the more you realise God accepts you, the more you accept yourself.
eg. i would say, 'i am a bit proud, but i'm quite kind to people but also a bit irritating' and i accept that this is how i am, and with God's help, i can get better. so if someone yells at me for being irritating, i say, 'yeah, sorry, i'm working on it'. but if someone says i am really mean, i check to see what they are talking about coz i know i'm not like that. i don't need to always try to please the other person when he/she is being mean and unreasonable, i just say, 'well, i don't see this the way you do, we will have to accept we disagree on this'. that way we don't get into a fight, but also i don't get bullied. (i used to be bullied a lot at school and work)
the more you accept yourself, the more you see that other people are not perfect either, and you accept them as they are and respect them (this is half way to love). then if you get married, you want the best for your husband, even if it means hard work like getting up early to make a coffee, but at the same time, you don't get bullied all the time, because you gently discuss any differences and make your point and listen to his point.
so when people take about martyrdom in marriage, they don't mean it's a really good think for one person to be an evil bully, they mean that it's generally hard being married because you have to care for someone and think of them as very important and try to help them in everything.