Is it normal to push love away while grieving?

My boyfriend's mother died very suddenly and unexpectedly 5 months ago, leaving him an orphan at age 36. His mother had raised him by herself and his father had remarried but died just a few years ago. His stepmother and half-siblings stopped talking to him after his father died, so it was as if he suddenly had no family left at all. When his mother died, I was the first and only person he turned to, and I held him all night and listened to him talk. He had to fly to another state to take care of arrangements and I offered to go with him. He tried to book a flight for me but nothing was available, so he asked me to come in the future to help him pack up his mother's house and be at his side at the memorial service instead. I tried to be as supportive as possible over the phone while he was away. We were in frequent touch and he told me everything about what he was feeling and going through. But when he came home 10 days later, he was very distant and strange. He seemed confused and said he didn't know what he wanted. He abruptly said he needed to take a break from our relationship and asked me to leave his apartment. He said I had been the most wonderful and sweetest girlfriend and that he loved me but that he just couldn't be in a relationship with anyone during this time. But he also kept saying that he didn't want to make a rash decision and to give it some time. I knew I had to set my feelings aside and allow him whatever he needed, even though I was devastated. I tried to give him space but also still be there for him, so I'd occasionally (every couple of weeks or so) send a short and kind email or text message. I did speak to him by phone for about an hour a few weeks later and he told me that he felt like a basket case and couldn't sleep. I tried to go help him with his mother's house but he turned me back home after our flight landed. Finally, 2 months later, he sent me a very terse and cold email that simply said there was not a possibility of us getting back together and that he felt there needed to be considerable time and distance before we ever talked again. No explanation or any words of kindness whatsoever. He sounded so different from the person I once knew. I'm having trouble accepting that this could really be the end. I keep wondering if there was anything I could've done to prevent or save this - whether I wasn't there for him enough in the beginning, if I gave him too much space or not enough, if it was a terrible mistake to get on that flight to try to help him, etc. Everyone tells me that doing that was an amazing selfless act of love on my part and wasn't inappropriate, but it seems like he was upset and disturbed by my gesture, perhaps due to his mental state while grieving. I only had the best of intentions and it doesn't seem like it should be a reason to push someone you care about entirely away and just completely refuse to talk. It was as if I had wronged him deeply but I don't know what I did that was wrong. Over the months I've read so much about grief and tried to understand what he is going through, but I still can't understand how his feelings could have changed so drastically when we had a great relationship before and he always seemed so deeply in love and sure of our relationship. I know he had to deal with a harrowing and traumatic experience, but why would he turn away from my support and cut me out of his life without explanation when he can still treat everyone else in his life as normal? How can he not miss the life that we had together? We were in a serious relationship and the love we felt for each other should mean something and not just evaporate into thin air. Can anyone help me with insight as to why he might have done this and whether it's likely he'll ever come around with time?