In this case I would analyze the situation in a comparative way, because it looks like you are in love or in lost with two people at the same time, and if you want to know how to get back with your ex when you are involved in another relationship my best advice is not to have a relationship with two people at the same time, but you will do it anyway, that is why you are reading this article.
Now to make things easier, I would say try to analyze each one and understand witch one of them you like the most and witch one of them you would be happier with.
Make a list with everything you like in one of them, and think about how they behave with you, how they treat you, what they do for you.
Think about how they make you feel.
Last but not least remember what other people think about them and your relationship, if you happen to know any opinions.
After all there are always people with more experience than you.
Then do the same to analyze the other one.
Think carefully when you analyze your ex, because you already broke up once, could this happen again? On the other hand pay close attention to the new one because you are still knowing and learning about each other.
Well, analyze and find out witch one of them make you happier, and make your day brighter.
And enjoy it without hurting the other one.
Just make it clear that you make your choice, whether is to get back with your ex or not and Good Luck!