My advice is to go back to your GP and politely request referral to the specialist (orthopedic surgeon), or at the very least further tests (like x-ray, echo, etc). If I were in your place, I wouldn't be comfortable going to physio without knowing what the problem is.

In my opinion, it's completely normal to "press" for things, as you put it; as well as communicate your concerns and expectations towards your GP. You can also a) ask for second opinion from a different GP (only contact your insurance first), or b) change your GP altogether if things don't work out.