I have the same situation. Sometimes it’s so painful I cannot really walk. I got my gynae to refer me to a physio. The exercises help with short relief but it doesn’t go off fully. One advice is dont wear pants or underwear standing. Basically dont do anything that you requires you to balance on one leg. Also dont do deep squats. The weight when you stand up again can be too much for your hips. Minimize walking up and down stairs as well, the movement gets your pelvic bone to over stretch and would hurt you more. Small and slow movements are recommended to lessen the pain till you deliver. Typically, the pain will go off around 2 weeks after you deliver
Have u tried using maternity support belt? I also have the same pain and using the belt it does help to support the heavy belly and pain. Am a nurse and i need to walk alot too. Take it easy walk slowly and have plenty of rest to ease the pain.
Unfortunately no remedy to ease the pain on the groin area. Perhaps baby's head turn down and ready to engaged through birth canal. As youve reach third trimester you will feel the pain near the groin area.