Tinnitus is scary stuff. Try taking a break from stimulants, reduce stress, do cardio, take your fish oil, etc. Some types of nootropic supplements might be helpful, but I'm not an expert there. Anything that gets blood from your heart to your ears should help, so yes, blood pressure is an important factor.
And, of course, stay away from loud music, or actually any loud sound for extended time. Even things that are only sound a little bit loud can end up doing damage if you're exposed to it for hours. But if you've had it for 5 months, it's certainly bad news.
Some of it just comes with age. Those little hairs in your ears simply aren't going to last forever, not without miracle stem cell cures that we probably won't ever see due to politics...
You should still see a doctor. My tinnitus sounded like a CRT monitor, so high that most adults can't even hear at that frequency. It eventually either went away or the brain figured out how to tune it out. My hearing certainly isn't as good as it used to be, but with all the noise exposure I've had, I'm surprised it's as good as it is.