The most difficult question to ask yourself is, should you get back together? The answer you will find is within yourself.
Questions you need to ask yourself is why did you break up in the first place - Did someone leave the relationship? Was there physical abuse or emotional abuse? Sit down and write down the positives and the negatives about the relationship and see if the positives outweigh the negatives.
The other thing to look at is does your ex want you back? There may be too much water under the bridge to get back together but if you have wondered whether you should get back together then there could be a small percentage that you want to.
The saying..
better the devil you know than the one you don't comes to mind so tread carefully.
I would say ask yourself why you broke up and take it from there, if you still have feelings for your ex then go for it but remember, whatever the reason for breaking up, could occur again.
How would you know if you should get back with your ex?..
...
by a gut feeling you have.
I would discuss things with your friends and see what they think, they would probably put more light on the subject being outsiders of the relationship.
Don't dwell on this, do other things to take your mind off it, you must evaluate the situation totally before getting back with your ex because you don't want to be hurt again.
Your emotions have already taken a beating so you don't want that to happen again if you can help it.
Look at the positives and negatives before making the decision.
Stick to a plan and rely on friends and family to help you out, you will see a light at the end of the tunnel.