You have not 'broken' up for real yet. You need
closure. You need one more time to sit down with him and TALK - not messaging, no SMS. Look each other straight in the eyes while talking and get the answers you need.
You also need to let him know that if he is interested in other people, then freindship is the only thing you can accept, and he should respect that.
He has no right to ask you all these questions. If he is a 'control' type, you need to avoid him anyway - that's not a good basis for any relationship.
Good luck, and keep us posted.

Communication is the key to any relationship - and I mean really talking with each other.