Some basic causes. Tinnitus can have many causes, chronic loud noise exposure, drugs like asprin, congested ear canals, diseases like menenier's disease (tinnitus+dizziness) having had a severe concussion or brain injury. Some are treatable but let your primary care doctor sort it out. They might need to send you on to an ENT too. Many cases can't be treated but there are some novel treatments as well.
Look for triggers. Agree with ENT workup, focusing on reversible causes. Unfortunately, most people with tinnitus do not have one of these causes and end up with purely symptomatic treatment; this is only partially effective and can have significant side effects. As frustrating as it is, i often end up just recommending a white noise generator.