Says we should work on each other

So my bf of a year broke up with me and told me that we need time apart to work on ourselves and then we might be able to get back together after doing so. I'm currently pregnant and didn't expect this at all. He says he misses me and still loves me but we need time apart. How can he say he misses me and loves me but breaks up with me? I'm so numb and it's literally destroying me because I love this man so much. I don't even know what he wants me to work on. I didn't think our relationship was that bad.