Hi Dayl,
Usually I just lurk, but I read your post and thought I could relate. In January, I sat down at my desk and put my headphones on as I always do, with the intent of not disturbing my neighbors by listening to the speakers. The headphones I have are a fancy type with a rotary knob. At some point, the knob got turned all the way up (it could have been bumped, I may have turned it myself when the computer volume was lower, who knows). Anyhow, when I clicked "Play" on my Music service, the music came out and the music was so loud, I struggled to get the headphones off. At the time, I didn't hear any Tinnitus, but a day or so later, I was quietly listening to music when I heard a ringing in my ears. I took the headphones off and the ringing never went away.
I had other stressors at the same time the ringing started (started a new business, quit my job, had a beautiful little baby). Those other stressors caused me to grind my teeth and clench my jaw as I slept.
After the Tinnitus started, I went to the Emergency Room, the ENT, and then again a month later upon his request (and I have no idea why he made the follow-up request), as well as to a GP and eventually one dentist, and then another dentist (one who had experience dealing with TMJ). I had a special dental appliance made for people who chomp, grind and clench their teeth in their sleep.
Eventually, my Tinnitus got considerably better. It may have been time. It may have been the appliance. I don't know.
The sound I heard was identical to a jet-engine, sitting at the end of a runway, idling. Sometimes, the sound would move to a higher pitched tea-pot whistle. In the first two weeks, the sound would move to both ears. Now, it's mostly a jet engine of a plane that's been recorded and played back on the lowest volume setting, in a single ear, followed by a little bit of static. It has improved quite a bit.
While I thought for months the headphone incident was the cause of my Tinnitus, I think it was more likely an additional catalyst, one with an organic basis, made worse by stress-related issues (the grinding and clenching made things worse).
I think oral steroid medications are often prescribed by ENTs for Acoustic Trauma during the early onset, so it may be worth finding a specialist. I had gone to see an ENT who seemed to know little about Tinnitus, so a Tinnitus specialist can sometimes help.
The statistics show about a quarter of military returning from Iraq and Afghanistan have some form of hearing loss or Tinnitus. There is probably a support group within the military, but the British version of the ATA lists local support groups which can help (I forget the name).
If your mum was your only support network, you'll need a new support network, with or without the Tinnitus. Military service is hard. That being said, I greatly appreciate your service.