I was diagnosed with chronic venous insufficiency. What should I do to treat it?

See an expert. This is not a simple problem to answer here- some might say wear stockings, or get some treatment. This needs a diagnosis and then treatment. A surgeon who specializes in vein therapy is best to guide that therapy and answer.
Venous insufficency. Evaluation with venous Doppler sonogram will identify source If it's superficial veins then thermal ablation would be of benefit.
What kind.. Did they tell you if it was deep or superficial venous insufficiency? You should see a vein specialist for appropriate recommendations for treatment.
Deep vs superficial. As dr. Oren mentioned, it is important to know whether your venous insufficiency involves your deep or superficial veins. If superficial, there are a number of treatment options that go all the way from wearing compression stockings all the way to endovenous thermal ablation. If the insufficiency is in the deep system, there are fewer options available to you and are commonly more invasive.