The main thing is don't rely only on ginger if nausea lasts for months. This could be a complication that needs medical evaluation, not self-treatment with herbs. Ginger is good as a supplement, but not as a replacement for seeing a doctor.
As for ginger itself, it really does help a lot of people with nausea - that's not made up. The mechanism works at the level of your stomach and vestibular system, so the effect is real, even though it's not universal. It works for some people, doesn't work for others. Ginger tea, ginger candy, fresh root - you can try all of it without risk if you don't have contraindications like ulcers or blood clotting problems.
But here's what matters: if after a couple weeks of regularly using ginger nothing's changed, or the nausea is getting worse, you need to see a doctor. It could be related to lingering effects from the illness, but it could be something completely different. Better to figure out for sure than to wait months for tea to work a miracle.