And I wrong?

Been with my now fiancé for almost 4 years and we just got engaged a few weeks ago. Our 4 year anniversary is next month on September 25 and he asked me if we wanted to go and elope just us two & have a nice mini vacation in maybe Las Vegas or San Diego, ect. I agreed and I thought it’ll be nice. Now, we’re in no rush and We don’t mind at all waiting until next year to get married and have a wedding. The thing is, I’m not sure about even having a marriage because of the cost and the overall stress of it. I don’t personally care for it but I’ll do it for my family and friends I guess as entertainment. Well when I told my mother she seemed upset ( which Is understandable) but she also made a side comment that wasn’t funny or necessary. She was like “haha.. his debt will become yours) I’m like wth? Was that necessary? My fiancé isn’t even in debt so idk where that came from or why they was said. Anywho I brushed it off. Then then said I needed to protect myself and get a prenup because after I finish school in a few months I will be making much more money than him. my fiancé doesn’t mind signing a prenup or anything from me. He says if it’ll make me feel better he doesn’t mind as he doesn’t care about what I’ll be making after school is over this year (could be making you to $150,000+) and my mom insist on me getting one just because. I feel like she’s too into my business and that, that’s a bit much. She also tells me to wait and having a wedding next year but with WHAT MONEY?? I don’t have anything saved for this and I feel like it’s adding even more stress to me because now I feel the pressure is on... Now I’m beyond stressed & i feel the little happy moment I wanted to share with her was ruined. My fiancé says we can wait next year or even the next and he’ll sign whatever to make my mother feel better but I feel like that decision should be between us and that it’s a bit too much and idk about doing all of this at all! Am I wrong for being at my mother? Should I just wait???