<human>: Can you condense the text into a few key points?

For some backstory, me and my ex dated for close to 2 years and 9 months and overall we had a good relationship except for some things. First off, she did cheat on me and I know that's a major red flag but we put it behind us.

We broke up in September and we hadn't really talked much for 5 months. We tried to remain friends because we had played such a major role in each other's lives and she's honestly my best friend. At first, it was kinda awkward because I still had feelings for her, but as time went by it got a bit easier. 

Things were going fine until we decided to meet up to talk one night because we were both fighting over really stupid things that we needed to talk about. And we ended up making out and having sex. At the time, she had a boyfriend and I had a thing with another girl so we both told them. 

Now, me and the girl I'm with are okay after I talked about it and gave her some time, but now my ex and I are no longer friends. Honestly, it really sucks because I know part of our relationship was rocky but she's literally the only person I feel I can come to with anything or talk to when I need to.

I really like the new girl I'm with, but I don't know what to do because obviously she hates my ex and I feel like my ex and I have a lot of unresolved issues I need to work out. This whole situation sucks because some of my friends literally won't talk to me again if I got back with my ex, but I don't know if deep down that is what I want or if I'd be content with just a friendship. 

I love her so much and I know she didn't treat me how I deserved to be treated(towards the end of the relationship), but lately I just find myself dreaming about her and missing her being around. I have no idea what I should do, and I'm open to any advice. Thanks guys/girls.
<bot>: I feel like me and my ex have conflicts we need to resolve but we aren't friends anymore and I don't have a way of approaching it.