Sorry to hear that. From what I have observed, it takes a lot for an INTP to initiate the break up conversation. It's very much over for them by that time. He hasn't talked to you in three weeks? You are done. He is trying to let you down gently with your new arrangement and is hoping you will use the time to get over him. He most likely doesn't want to deal with any upsetting emotional drama. Did he suggest seeing other people? You're definitely done.
What to do. I wouldn't let my own feelings cloud the reality of the situation. (Which is that he broke up with you and apparently hasn't talked to you for weeks. And possibly suggested seeing other people during your "break".) I would send him a brief, non-hysterical email. I would say that it's been a few weeks and you haven't talked. I would tell him he has permission to be honest. I would ask what prompted the break up. I would ask him if he'd prefer to just end things cleanly now and let him know you are ok with that. You will get the truth out of him then instead of his attempts to avoid dealing with your feelings at all costs. And hopefully you can deal with the answers if they aren't what you want to hear. At least you'll know and can move on.
I watched an INTP I know break contact with someone he was soooo over, and had been for months and months and months. He thought she would get the message if he just didn't talk to her. He was shocked that she didn't get it. I wasn't. She was holding on to how she felt about it, rather than looking at the honest truth of their interactions. He would have done anything to avoid a big dramatic scene. From that, I've concluded that you have to give the INTP explicit permission to not just say what he thinks you want to hear.