How can you mend a broken a heart?

My ex-boyfriend just recently broke up with me. I just can’t believe he’s gone, everything just hurts so much, everything reminds me of him. He admitted to me, he doesn’t care about me anymore. I cry myself to sleep every night, I dream of him and every morning I wake up to the same painful reality. We were so in love, we made plans together, he promised me he’d always love me no matter what. Maybe this is all my fault, as he says it is but I never knew it could be that easy to put aside his feelings and forget about the love we shared. My heart hurts so much, I know I can get through this. I know things always get better in time but I’m still so in love with him. A part of me knows I need to move on and the other part of me doesn’t want to forget him. No one really understands how I feel, everyone is telling me it’s my fault! But I gave him my all, I loved him with all my heart. The days just get longer and lonelier and my nights get more and more sleepless. I’m trying to keep myself busy, trying to carry on like nothing’s wrong. So why does everything still hurt so much? Why do I still love him? Why do I cry and cry when I know no matter how many tears I cry, nothing is going to change? Someone please help, how can you mend a broken a heart?