Diagnosed with GD. Freaking out. Gynae feels harm might have already happened by 30 weeks

Looking for experiences from anyone diagnosed with gestational diabetes around 30–31 weeks, especially if you had mild polyhydramnios.
I’m currently 31w2d.
Ultrasound findings (fetal medicine specialist):
EFW: 1535 g (56th percentile)
AC: 61st percentile
HC: 86th percentile

Mild polyhydramnios (AFI 22 cm)
BPP 8/8
Normal Dopplers
Detailed anatomy otherwise normal. Kidneys, bowel and brain looked normal on the fetal medicine scan.

My detailed anomaly scan at 19w5d was also normal.

I recently started checking sugars at home because of the polyhydramnios and failing the OGTT test.

Most of my readings are within control using a home glucometer.

My new OB examined my abdomen and felt the uterus was measuring closer to 34 weeks, and said gestational diabetes may already have affected the baby. I also mentioned pelvic heaviness and she said since I did not do any fitness activity in first 2 trimesters, I May have to live with it. People who start early don’t have this heaviness.

Has anyone had a similar combination of:
Mild polyhydramnios,
Baby measuring around the 50th–60th percentile overall (but larger head measurements),
Suspected or newly diagnosed gestational diabetes around 30–31 weeks?
Did the baby’s growth remain normal after glucose control, and how did things turn out?

I am freaking out frankly. Have been crying since hours now and cannot help.