Facet joint and psoas issues

Hello I'm currently having physio on a re-occurring issue with my lower back. Sessions so far have been focused on relieving the tension in my lower back. The region is locked to protect the issue of potential facet joint syndrome which is an old problem I've self managed reasonable successfully for the last 15 years.

I am now having significant issues with my hips on both side. I really need advice on how I go about identifying what the actual cause of these issue is rather than just trying to manage the symptoms which are just getting worse.
I'm not is the position to keep paying for a private physio which, despite providing initial relief has not been able to identify the actual issue. I am now not sure which type of expert I need to lean on the root out the underlying problem to then create a recovery plan.

Should I just visit my GP and take a ticket, or is there any type of expert I should be trying to find locally?

thanks