My gynae advised me to lift my feet up when i’m lying down. Personal thing I did was to wear slipper around the house and stop wearing sneakers and just wear crocs (super comfy) so my feet can breathe. Not sure if this will help for you.
You may want to read this article https://www.healthline.com/health/pregnancy/swollen-feet-during-pregnancy#causes
other than walking, elevate your legs, you do need to drink more water. it does works for me.
Water retention is normal. Do yoga safe for pregnancy for aches and cramp
Elevate your legs and wear compression socks!
Swimming is beneficial when pregnant