<human>: Can you give me the gist of the text in a nutshell?

I have been dating my boyfriend for about 5 months now and I would say we are getting pretty serious. We can see a future together but we're also aware that we're in college so we don't look that far into it. It's been great so far but recently his ex transferred colleges and is now going to the same school as us. They dated for about a year and 2 months and he dumped her because he just lost the connection with her and couldn't see them together anymore. We started dating about 3 months after they broke up. Anyways, I've seen her on twitter and she's seen me, even followed me and started favoriting tweets and things like that and I honestly didn't care but now she's harassing me on twitter and getting all her friends to do it and I want it to stop but I don't know how I go about doing that. I feel like if she keeps up the stalking and bullying it might put a wedge between my SO and I. It's nothing wrong with him I just have major insecurities and this entire thing is throwing me for a loop. How do I make her just go away or not be so important to me? Please help. Anything would help at this point.
<bot>: His ex moved to our school and now I don't know how to deal with her bullying on social media and the constant insecurity I have of her being so close.