You are still a parent!

Whether your child was stillborn or died as a newborn, does not change the fact that you are a parent.  Death, whether unexpected or anticipated, does not invalidate your relationship with your child.    You need to do the things a parent does for a new child:
Hold her, giver her a name, confirm she is yours and claim her as your own, examine her little body and see what features resemble you or your family, dress her, take photographs (and lots of them!), preserve a lock of hair or make fingerprints/footprints, marvel at what you created, talk to her, sing and coo over her, love her and never forget her!