I just can’t believe this

So i just got engaged last Sunday evening and all and I’m young I’m 19 but he is 23 so he wanted to go ahead and get married and start a family and i feel like I’m ready. I know there is going to be a lot of people that say I’m too young and I’m not ready buuuuttt he has a really nice job making $25 an hour works 12 hour shifts everyday except Monday and Sunday and he gets a $400 bonus each month if he doesn’t call out or anything he has amazing insurance and benefits paid vacation and sick days so a really good job . I said all that too say that we can afford a house a living and all I have money saved up he has money saved up plus that job to where we can go ahead and get married and start a family and I can be a stay at home mom and all that good stuff. I’ve been really trying to work on not too let what other people think of me get too me and not too care what other people think just too do what i need to do and looking back on everything I have gotten better. So yesterday i posted on my Facebook that I was engaged to my fiancé and I got so many nice supporting comments which I did not expect untilllll this one girl I blocked beacuse she has something against me I have no idea what it is she just hates my guts I’ve tried to talk to her reach out too her every time she cusses me out she was in the hospital went to visit her there but no she just hates me so finally I just blocked her everything. My SO had her on Facebook they knew each other but like didn’t talk kind of thing so she was able too see my post beacuse of he had her on his page. She commented “congratulations but didn’t y’all just get together a month ago” which we got together 4 months ago been best friends for 4 years . In my option why even say congratulations if your going to put something negative like that . So my fiancé messaged her saying if you we’re concerned about how long we’ve dated or wanted to know you could’ve messaged me about it and we’ve been dating for 4 months and known each other for 4 years and she blew up on him saying how I’m a hoe and a whore and she claimed she went to church with me which she did for like 3 months. She called me all these names and all this bs and how I wasn’t good enough for him and how I’m using him. She used to have this major crush on him and tried to sell her nudes too him. Then she brought this girl that my fiancé used to be friends with but is not anymore due to drama. This girl that posted all that was like arn’t you going to listen to your friend and he was like we are not even friends anymore due to drama and the other girl was like okay I’m going to tell her that and he was like ok? And she texted me making threats saying she going to get someone to beat me the fuck up and all then about 30 minutes later she texts me personally saying all this crap about me and how I need to keep my mouth shut when I didn’t even say anything too her and said if you wanna reply to this you can get my address just a bunch of drama. What do y’all think on the subject why do you think they started like that when I’ve been nice my fiancé was nice I don’t understand it. Do you think I should take the threats to the police or not ? Thanks in advance and thanks for reading