Does she not love me if she doesn't want to marry me?

I've been sore with her for the past few days, and she's been trying to make it up to me. But I really can't help but to feel like crap because she told me she doesn't want to get married but wants to have a live-in relationship with me. She's just afraid of what marriage life would do to a perfectly good relationship. She kept reassuring me she has no committment issues but feels no-marriage is the best way to maintain a relationship. She's 22, do you think her opinion on marriage will ever change? I can't help but to feel like it's a personal attack towards me, as though there's something wrong with me, and that's why she doesn't want to marry me. I envy my friends because all of their girlfriends have intentions on marrying but not mine? I've been quite bitter with her lately, and I know she's getting pissed by it.