I agree with Velo, that the location seems to be too far back for a ZGT which is a good thing!!
As for what it might be, if those 2 scabs are bite marks then it could just be a regular abscess, and compressing is the way to go. If its scabbing that is spreading over the lump then its possibly its still an abscess but not a bite one, more of a salivary gland one like my Twiggy had. I have lots of gross pics and a thread on here I can dig out if you think its more the 2nd option.