I wouldn't say you're being a jerk, but you're not trying very hard to see things from her point of view.
My best friend and I have been BFFs for 15 years. She's single, unmarried, no kids, never had a job, parents pay all her bills, and she's working on her masters. Obviously she thinks she should be the center of my universe.
I'm a married mother of two (third on the way), my husband and I both work full time, and our kids both participate in multiple extra-curriculars. The weekends are usually dedicated to either family time or home improvement. My social life is pretty much non-existent.
You say your friend calls you once or twice a week? That's WAY more than I call my BFF. I send her texts now and then to tell her I love her or I'm thinking about her, but she has learned that a social life is not even in the top 5 of my priorities right now.
Obviously she's not meeting your needs, and it's ok for you to be upset about that, but don't hold it against her. She's living her life. Be happy for her that she's in love. Text her now and then to tell her you are thinking about her. Don't pressure her, it will just cause her to resent you. When life settles down, she'll know you were always there for her, even when she wasn't.
In the meantime, just accept that she can't be the friend youneed her to be. But don't give up. Because you also need to be the friend SHE needs YOU to be.