Hip or groin pain advice

Gearing up to a 10K adventure run (a few weeks back now) I was steadily increasing and following a sensible training plan to get to around the 5 mile mark about a week and a bit before the big day. About half way through the 5 miler I felt a niggle in my right hip that progressively got worse as I ran. The run itself was a medium paced near flat run, so I didn't expect anything could go wrong!

I suffered from shin splits in my early training, but have been free of them thanks to careful training rest and a foam roller for weeks now, so out of the blue this was a bit of a shock. 

I have no pain at all when sitting or walking, but running a decent time 5K really aggrovates the injury and when I'm not running, lifting my right leg (climbing stairs, putting on a shoe or getting in the car, etc.) causes a really sharp pain, pretty much where the front-facing tendons meet the front of my pelvis, tending towards my groin.

The pain is deep (pressing on the muscles of my groin / thigh or the same surface tendons doesn't hurt at all), so I thought it might be my actual hip joint.

I rested for a full week taking ibuprofen on alternative days and it didn't seem to make any difference. I've tried pretty much every groin and adductor stretch there is (I was careful not to make it worse with these too!)

Phew. Long story... I was wondering what the advice is for something like this. Should I see a physio or my GP?

Is there anything else I can try to work out what I've broken?