Scared angry heartbroken

I found out I was pregnant at around 4 weeks. The moment the test come back with a positive I started to bleed. It was a little spotting so I did worry much. Later that day it turned out to be a lot of bleeding. Call the doctor who sent me in for hcg test. When it come back at 35 they sent for another 3 days later. That time it was 78 so they was ok with it but wanted me to come in for my first appt in 2 weeks. At the first appt they done an US and showed me at 6 weeks. I was a few days different so no worries. The heartbeat was good at 122. Yesterday I went for an elective scan to hear the heart beat I should have been 10 to 11 weeks. The baby measured at 8 1/2 weeks with no heart beat. I went to the doctor who confirmed what the first scan showed my baby died 2 weeks ago. This is my second miscarriage but now I have to have a d&c. I don't know what to expect. I don't know why. I have had other children. I keep going. Over the things I did that week and trying to figure out why my baby died inside of me. I keep seeing the look on the woman's face when she had to tell me something just was not right. The look on my 3 year old face is he was excited to see baby Darrington. I am passed wanting to hit things  just can't stop crying.