Should have proposed

Intro:
So my ex (GirlX) and I broke up 3 weeks ago. Since then I have made several of the instinct mistakes: being needy, texting too much, acting emotional, etc. Also we go to church together, so people like our pastor and my people I reach out too also happen to be her friends. I guess that means they fall under the coworker rules about not talking to them, which I did. And she got mad.

Background info:
GirlX and I met through our church when we were around 13-14. Shortly after meeting we started flirting on and off. We dated for about a month once, didn’t work out well. then we weren’t together for a while but were still friends. Her freshman year of college, my senior year of HS we got together and actually figured some stuff out and were together for about 2 years. She started to get attention from another guy and things fell apart for a while. However we lived right next to each other and patched things up after a bout a month. The next time we broke up was about a year later. We had fought over weather we were going to have birth children or adopt. Weird thing to fight about I know. Again after about a month we got back together.

Now:
Fast forward a year and you’re at the current break up. She had been prodding me for years now about getting married. She is Graduating in May. We have a small fight, talked very little for a couple days, then she asks me to come over and talk. I think it’s just over the small fight so I bring the dog (part of what we fought about) with me. No she wants to have a big argument about where we are going. I’m exhausted and fighting with this dog that won’t be still. So when she gives me an ultimatum about showing her that I’m working to start a life with her I pretty much tell her no and walk out cause I’m an idiot.

The following morning I go back to her house trying to fix things. She tells me no. The next three weeks I spend trying to not be annoying and do the no contact, but failed. I’m sure it doesn’t help that so many people have asked her about it (same church, same friends, same pastor). She now wants nothing to do with me and gets mad at our friends for talking about it.

so 14 to early 20’s I’ve had feelings for GirlX. I may have been a moron about it, but I’ve known I wanted to marry her since we were maybe 15-16. She at least used to be my best friend.

So what do I do? How/Can I fix this?