Confused

Hello ladies.
My husband and I lost our beautiful Daughter at 21 weeks. Although we have both received overwhelming support from our family & friends I can't help but feel alone & totally miserable & depressed.
I know it's normal and part of the grieving process but my emotions go from 1 extreme to the next. One that has stayed with me is extreme guilt. I feel so guilty driving past the cemetery and not going in, I feel guilty for laughing & for not thinking about her every minute of the day.
When she was born her umbilical cord was twisted like a telephone cord and although we don't know if this was the cause of her death & still awaiting autopsy results it's painful to think she could have died slowly.
I see other baby girls & it breaks my heart, but I can't help but feel like having another baby will bring her back to me, has has anyone else felt like this? Is it normal?