tired and lost

Hi, I'm new here. I recently went through a breakup where the person I was falling deeply in love with unexpectedly left me, without offering any explanation. I know it is normal to experience depression, but that doesn't make it any easier. I try and stay positive, but there are days that I just slip into bouts of lethargy and melancholia, and sometimes accompanied by the feeling of not wanting to be alive, at least until I feel better. And I know this isn't true, but sometimes I feel as though I will never get over them. I don't know what to do anymore. I can't look at them without feeling hurt. I can't go to places or events that raise the possibility of his presence. I'm scared, sad, and tired. I don't know what to do anymore.