Hi, i currently suffer from chronic shoulder instability since i first dislocated in november 2012..i now have a hard lump on the midshaft of humerus, h?

Needs a workup: There really shouldn't be a connection between instability in your shoulder and a lump in your humerus. At least an xray should be done, being evaluated by your orthopaedic surgeon again would be necessary.

I don't : Understand why you would have a lump mid shaft? This may be completely unrelated or related to hematoma or trauma from repeated dislocation. May want to get some xrays or MRI of the humerus.