Premarital Sex?

I grew up in a conservative environment. A religious family and a catholic school. I've had a boyfriend for 19 months now against my mother's will & she doesn't know. These past few months, we had sex for the first time and I was urging him for months. Premarital sex. After months of that thing, he's still good and still like before but I think I'm falling out of love now. After doing the thing, I realized that I'm not sure if I want to spend my life with him. Since I had this belief in my childhood that whoever I have sex with the first time should be my last. Now, I'm quite not sure. I kind of regret what I did but not so much because of the lesson I've learned. Anyway, I'm really confused and scared. What if I broke up with him and I'll never find another one again because I'm no longer a virgin... it's a big thing in my country btw and im a girl