My family dislikes me - what do I do?

My family consists of my older sister (27) and my mother and father.

I started dating my husband when I was 18 (he was 26) he was a single father of 4 living in a bad side of town. I eventually moved in with him and my family told me no, no, huge mistake, I'm throwing my living away by being with someone with kids. I did it anyway, my husband and I went through terrible times, financial struggles like no other. We built up together, bought our first home together, worked through every struggle, eventually got married and had a daughter together. I'm now 20 and my husband is 28.

My family hates my step children, hate that I care for them. Their mother abandoned them so I stepped in and care for them like my own, they love me and call me mom, not by my first name or step mom.

My family calls me a failure, told me I threw my life away to become a "slave mother",they don't invite me to parties and when my mother calls me she just talks about how terrible my life decisions have been. They say terrible things about my step children, even though they are JUST KIDS! "if you come over you better not bring those kids" my sister has even made her own son (he is 9) say terrible things about them "Your children are annoying, my mom says. I bet they smell, disgusting"

I am sad because my family does not involve me or respect me, my husband is upset that I still make an effort for them to at least like me. I'm on the verge of dropping them from my life because their negativity is sucking the life out of me and I don't even freaking live with them.