can t stop thinking about my ex?

[Ruby]

There is nothing wrong in you thinking (just memories appearing) about someone you have been with and cared about for as much as 3 years. That's a long time. I sometimes think (happens like every now and then) even about guys I just spent 3 months with. It really depends on how deep the bond was and how much time passed.

And for you it has been only 6 months, that's not a long time gap. You need at least another 6 more to finally get over it. It is also good you deleted the contacts in social media, better if you throw out all his gifts (expect some really valuable ones if you have), delete photographs (why keeping things that are not part of your life anymore?) and most importantly - you should let your anger go.

I know you still got a part of you that is angry with him, for all the mistreating and misbehaving. As much as you keep it within yourself - you only poison your own brain. Let it go. Forgive his mistake, write it off to his stupidity and move on.

Your ex appearing in your head is normal. Not normal is when this starts ruining your current relationships.