The first step is to talk about it with a best friend or a counsular. If you do not talk to some body then you will just bottle up all the feelings insde and end up crying for hours and hours because you cant hold it in anymore.
You might want to ask you ex what went wrong, but only if you can control your emotions. You dont want to look hurt because they left you. If they dont want to talk about it then they either dont know how to explain it, or just dont want to be in a relationship.
the next step is also an important step and it is deciding what you’r fellings are for that person.like if he/she had done something so terrible that you could never take them back then it would best to just forget about that person and move on. this step will be easy but if u still have feelings for that person then you might want to keep readign this article.
now you are deciding if u would like to still be in tha persons life such as a boyfreind or girlfreind or just as freinds but from experience the freinds route isnt the best route always. Most of the time there is a really awkward feeling between you to when you meet sometime in the future.
if you would still want to be in this persons life then you ussally have to start over in there book as a freind and then work you’r way back up. This takes a while but is totaly worth it is you have feelings for this person and truley beleive they are the one for you.