Don't Know Where to Turn ...
The university-wide Student Union (not to be confused with the Oxford Union)
The platform you access to vote for your GCR Committee members, but it's also so much more:
The Oxford Student Union represents the interest of ALL students through the Student Council that comprises six elected Sabbatical Officers, a Steering Committee, seven special interest Campaigns, internal and external trustees. They do the hard work of advocating, but they depend on you to inform what policy change is needed.
Approach the appropriate Sabbatical Officer and/or Campaign Officer for help or advice on a challenge in ANY aspect of your university experience that you are struggling to resolve, don't know where to resolve or is not being adequately addressed.
Other opportunities are to run for an office, volunteer and/or propose a project. If you're simply curious, Student Council meetings are open to all matriculated students of the university.