Struggling with depression after becoming a dad

Had my first kid 8 months ago and I should be happy right? But I feel empty most of the time. I love my son but I don't feel it the way everyone says I should. Wife thinks something's wrong with me. Talked to my doctor and he said it could be postpartum depression or just adjusting to fatherhood. Started taking an antidepressant and honestly it's helped but I'm still not myself. Anyone been through this? Does it get better?