Hi Andersson,
Don't despair. I have been in exactly the same situation as you. I've been sitting in front of the TV, not eating, not moving, just watching (and not very loudly either), believing I am doing well ignoring the tinnitus and all of a sudden it has just exploded in volume, filling my head with a loud, high pitched ringing. Last week, my tinnitus was really quiet in the evenings and I slept well for a few days and then all of a sudden, on Friday night, it was horrific, screaming away and I just couldn't sleep. When it happens, for the first few minutes, I am so shocked, I don't know how to react and then, when it doesn't subside, I just feel so distressed and helpless and I freak out.
Sometimes, it has taken an hour to settle back and at others, it has been the best part of a day, but it does always seem to settle down - even though sometimes I believe it won't.
My advice is to go out for a walk somewhere. Not somewhere especially noisy, but with reasonable background noise. The combination of traffic noises (I'm not suggesting you stand next to a busy road, but distant traffic noises in general), birds, the wind, rustling leaves have a really good effect at distracting the mind as there are so many, more interesting noises for your brain to tune into.
In fact, just as I was typing the last sentence above, it just flared up a bit, but I need to remind myself that in an hour or so, it WILL settle back down and in reality, even when it is bad, it probably is occupying no more than around 10% of my day as overly intrusive, that means that 90% of the time and my life, it is not a significant problem.
...and I promise you, I am not somebody that is in any way relaxed and calm about it, at times, it seems all too much for me as well - I am in fact that person that used to put in earplugs whenever staying at a hotel as any doors and footsteps around the building would irritate me to death.