Sorry to hear you are having tinnitus. For your sake, I hope you get it treated since it must wreak havoc on your enjoyment of music.
Two observations:
Tinnitus is a very complex condition, which I gather you have read enough by now to know. My wife had a low-level tinnitus condition for many years, since she was born hard of hearing. Many people with some degree of hearing loss experience it while many also do not. But when she was a victim of a rear-end car accident, the tinnitus became a full-throated roar, almost non-stop, for the past 10 months, with scant relief provided by physical therapy. The possible cause: injured sternonucleomastoid muscle pulling on parts of the ear that are responsible for conducting sound, causing the auditory organs to "self-generate" a phantom sound, much like a semi-taut string would if immediately tautened.
It may also be damage caused by headphone listening. I know a guy who incurred permanent tinnitus from long-term headphone use.
As for your audiogram, your hearing seems to be generally fine, except for a high frequency loss, as you noted. Doesn't look like you have a serious hearing loss at all since audible speech threshold starts in the neighborhood of 20-30 db. Not bad for a carpenter....