Is it normal to not want to go to mexico with husband...

My husband was born in Mexico. We have been married for over a year, and this Christmas he wants to go to Mexico and have me meet his family.

I am 20, in nursing school and work 2-4 shifts a week as a waitress. Although my husband has a full time job and no school, I am still expected to pay as much as he does for bills and whatnot. So I do. I still have to finish paying my school (1,000), and he wants me to pay for my plane ticket (another 1,000). I told him I won't be able to go due to the cost and he continuously calls me lazy, selfish, and said if I really wanted to go I would be working more.

In my opinion, I don't think he understands the stress of school and work. He constantly compares me to his sister in law who has picked up more days (exactly 1 day more, which is only 1 day more than I work, plus she does not have school).

I wanted to hear what other people think because I feel like I am going crazy. Am I selfish and lazy for not picking up more days to go to Mexico? I don't want to put myself on a pedestal but I feel like I work harder to better myself through education than he or anyone else has and don't get any credit for it.

Thank you in advance.