There's really no need to be desperate and depressed. After all, you've only had this for two weeks. And, for the moment, an MRI and cortisone are not needed.
But a plain xray of your pelvis would certainly be useful.
There really are quite a lot of possibilities, and the diagnosis can only be made after a diligent and thorough examination of your hip, sacroiliac joints and lumbar spine.
See that opening your legs, abduction, is painful, I would be thinking in the first instance of a hip condition. Look up Fabere test, really just the lotus position. Is it limited? Is it painful?
Pull your knee to your chest, and then towards the opposite shoulder. Limited? Painful? Or really are these movements full, but perhaps painful?
Run your thumb from the groin down the inner thighs. Is it excruciating?
The most likely causes are a femoro acetabular impingement syndrome, or a hip dysplasia, but like I said there are several others.
I would recommend you have a pelvic xray, and then start looking for a chiropractor who works with the hip joint. Ask before you make an appointment. Pain in the groin. Mention fais, do they sound totally at sea? Move on. Perhaps ask your local chiropractic association for someone who works with hips. A sport chiropractor would be a good idea too.
Let me know how you get on. I hope this has been helpful.
Now, nuff of that desperate and depressed stuff! If you're no better in three months, well then, perhaps.
Dr Barrie Lewis DC