Feeling numb

My boyfriend of three years broke up with me (one week after our third anniversary). I know we’re still young, 20 and 21, but I just feel so numb from everything. I thought we were okay but I guess not. I thought we were In love and going to be married at some point, but I guess not either. It’s been about a month and I just want to feel anything again. He told me that he just gave up on us and that’s why he left me but I don’t have a full explanation as to why. Heartbreak sucks, and right now that’s all I know anymore...