Does tinnitus tend to get worse over time? If so, is there anything to avoid to not make it worse?

Yes! Tinnitus is most commonly caused by loss of hearing due to excess noise exposure over time. However there are some things to know: if your tinnitus is only on one side or much worse on one side or if it is associated with bouts of dizziness, you should see your doctor about it. Rarely it can be caused by a tumor called acoustic neuroma, or a condition called meniere's.
See an ENT. Ent evaluation is in order if you have persistent tinnitus. In general, avoid intense sound, caffeine, alcohol, NSAID medication. Regulate your sleep and control stress. These measures usually help.