How long should a separation be before you reconcile?

Its been three weeks since my boyfriend left. How long do I wait? We have two children one together and one he has been raising since he was 5 1/2, on top of that we have been together for 6 years. He cheated on me 2 years ago and we moved to another state shortly after finding out. He stopped speaking to her about 9 months after we moved. We had been going to counseling for the last year and a half and finally making progress in rebuilding our relationship even going to be purchasing another house when I my suspicion got the best of me and recently realized he was keeping me in the dark with a few details about some things happening at work, so I got mad, made a scene at his work over the phone and told him not to come back. It has been 3 weeks and we haven't spoken about it. He missed his child's pre-k graduation. He didn't visit with the kids until this past weekend and it was just for a day. He asked for my mother to drop them off then asked a bunch of questions about me but said when he is ready to talk to me he will. I am scared to let go because there is a part of me that really does love him, and it is love, it is not the fear of being alone, I have done that and was happy for a long time. I just don't understand how broke someone has to be to go to this extreme. How long do I wait before just giving up completely? Part of me says just give him time another part tells me to just cut all ties. Any advice. I am beyond devastated.