Bonding with baby...

So i'm having trouble bonding with my baby. When I had my first ultrasound I cried. But after that i lost my connection. When i heard the heart beat the first time it was cool but it wasn't amazing. I bought a doppler to try to bond but... meh. I had my anatomy scan today, found out we're having a boy, saw him, watched him wiggle around and kick, for about two minutes. And it was so cool but it was like i was watching somebody else's ultrasound. Now when I look at the pictures it doesn't resonate "thats my baby" "thats growing inside of me" it feels like it's somebody else's baby. I feel like crap because i should be amazed, and in love, and thrilled. Thats how i felt with my nephew, first time I saw him i cried. I'm scared when the baby comes I won't feel like he's mine, or i'll get PPD. I'm starting to feel him move a little bit but even that doesn't connect. I don't have many symptoms and i don't really feel pregnant. I didn't have any morning sickness, i lost 6 pounds, no heart burn.... I'm so sad, i don't know what to do.