Hi kevin b,
don't focus on what happened and why it happened because although you want to know the answer it will not make any difference to what your tinnitus does. Just focus on trying not to react to the noise whatever it sounds like. I have screamingly loud tinnitus with various hisses and other sounds but most of the time it is no longer a problem.
It's strange really that the solution to dealing with tinnitus so that you're no longer bothered by it is the most simple thing ever! Just don't react to it whatever it does and your subconscious will start to filter it out of your awareness, BUT even though the answer is simple, I found it to be one of the hardest things I've ever done. The fear it made me feel was so intense it was disabling at times, so I reacted and then the awareness was greater and so on in a cycle till I finally realized it was absolutely my reaction and nothing else that made it louder. So, be kind to yourself and know that time will help. You can't turn back the clock and undo what you did and it is probably the anxiety of worrying about what you did that's the problem, not the action itself. Distract yourself, use relaxation, do whatever you have to, even if its just an hour at a time. The more you practise not reacting, the easier it will become.
You'll get there. If I could have taken a pill to end my life I would have done so for probably every day for 5 years or more but now it's just a slight annoyance some days and I know that I have a choice in how I react to it. If my thoughts become negative it gets worse, if I get my mind onto other things I 95% of the time realize that it's gone from my awareness again.
'Between stimulus and response there is a space.
In that space lies our freedom and our power to choose our response.
In our choice of response lies our growth and our happiness.'
I wish you well.