Physical relationship with girlfriend. Am I legally binded to marry her?

I had proposed a girl to be my girlfriend. After couple of months we had sex. At that time, I hadn't promised her to marry. This kept on going and we started to fall in love with each other. At times, the discussion of future also came up to which I didn't lie. I said ,"I would like to be with her". Now, she keeps on bringing the topic of marriage again and again when I have clearly mentioned that I don't want to talk about it as I am financially not stable and want to build my career first but she keeps threatening me that if I don't marry her then I will face consequences. Due to which, the feeling of love is seeping away and I feel like I am stucked. She has increasingly become a huge source of tension in my life. She won't let me work and build my career. She demands time more and more completely ignoring my career. If this is how she is then marrying her would be one of the biggest mistakes of my life but I don't seem to have an option. I mean, I like her and probably want to marry her once I am stable but I don't want to do it by force. What are my options?