Hi Kris and welcome!
My DD Gemma was also born at 33 weeks, weighing 1800g, & is now 9 months old. Her birth was a c/sec planned at very short notice. I've also had an abruption, with DD Sophie, unfortunately too early for her survival. Many of us have had scary histories, so you're not alone .
How is Chad going now & has he gained weight well? Several mums have commented on the disappointing weight gain until about 6 months, when they started solids. Are you having any paed follow-up?