Would commemorating their existence help with moving on? When your stillborn entered this world and you can't help but think about the date for the future years like an anniversary, you can wear a ribbon/string/jewelry on your pinky as to remember and also be your outlet to grieve about your little one. A blue ribbon represents miscarriage but can also mean a loss of a child. Another possible heads up if you find yourself confused about your pain in the future is, for some, the pain of losing someone born into the world, it doesn't get better after said period of time (like the first year). It hurts more and then gets better because your body and memory is processing the pain as well as stretching out the pain in doses so it won't be too overwhelming.
You can buy a jewelry in memory of your little one to carry around your neck. Perhaps their birthstone, a saying "Angel Baby", a pedant with engravings of the birth date, etc. Have a keepsake box for your little one's ultrasounds and hospital paperwork, small baby shower trinkets for when you miss you little one. It'll help with dwelling less with constant reminders of your loss.
Try also looking up articles and local support groups death of their living child as they will be more likely to correlate your feelings and subside your feelings by listening to their pain that you would consider more painful than your own.
Of course you can still do the other things that others above mentioned, but I don't need to repeat them.
I hope this helps!