nad1UK,
There are many causes of persistent anterior shoulder pain and it's not always a bony one. It is possbile, based on the description of your injury mechanism that you may have overloaded your bicep and caused injury along the bicep's attachement. More often it is possible to damage the labrum i.e. a rim of cartilage surronding your shoulder socket in which your bicep attaches to. A tear in the labrum in this regioin is sometimes referred to as SLAP lesion and sometimes it does not resolve spontaneously. It would be a good idea to see to a sports physician or physiotherapist for the diagnosis of this type of injury.
Of course, there are other possibilities but the chronicity, location and injury mechanism you have described fit this particular injury the best (and yes it clicks and clunk too). I doubt your current problem is a bony one as a humeral head fracture rarely presents as a problem beyond it's normal healing time frame i.e. 6-8 weeks.

Diagnosis of a SLAP lesion is Wikipedia reference-linkMRI.

Good luck,
M.