None of us here could possibly tell you what is going on with your boyfriend in rehab, but addicts in recovery are typically fighting just to get through each minute of each hour of each day. They need to be selfish in order to recover. It may not be reasonable for you to expect the same level of engagement with him that you are used to. He will need to focus primarily on his own needs and will not likely be capable of meeting anyone else's for a good long time. Now is a good time for you to focus on yourself as well.