<human>: Can you summarize the given text in a few sentences?

So I've been seeing this girl I met in one of my college classes for about a month and a half to 2 months, and we have an okay thing going. She makes me happy, I make her happy. But She's the first person I've seen since breaking of a long term relationship of over three years. At first things were great, but as the semester is ending I'm starting to feel like I'm missing my ex from the 3 year relationship a lot more. 

I just want some general advice, as I like this relationship and don't want to just end it, but I also wish I hadn't left my ex but I am like 99.9% we won't get back together, as she is seeing someone new as well and seems much happier with them than she was with me. I just can't get over her no matter how much I want to.
<bot>: In a new relationship that makes me happy, but I miss my ex way too much. What should I do, is there a way to get over this?