We broke up yesterday and I just want to know if she broke it off with me because of something I did? I'm just not sure if it's a good idea so I thought I'd see what others would do if they were in the same situation?
Personally, I wouldn't text, but if you need that closure, and didn't get any answers when you broke it off, then you can always take the chance and message.
The only thing you should text her is that you want to speak to her in person to get an honest explanation. Texting is too impersonal, detached, and cold. You deserve a reason, but texting important things like this leads to unintended consequences.