I can understand your concern.
Here are a few things that you can try that can help you in this condition.
1. Take things slowly, start with foreplay and then proceed to intercourse.
2. While doing intercourse also, do it slowly because doing fast can lead to premature ejaculation.
3. While you feel you are about to ejaculate, stop for a few seconds and then start over again. This start/stop technique can help you if you implement properly and can increase your duration.
4. Do pelvic floor muscles strengthening exercises.
5. Yoga/meditation can also help.
6. Quit smoking, smoking decreases the ability to hold erection for long.
7. Taking Viagra is fine but first try these above listed methods.
All the best.
Dr. Anil Kumar Jain.
Early ejaculation could be due to many reasons. Anxiety being the most. So first try relaxation techniques and distraction method. Then try to cut down on any habits like alcohol, smoking or drugs. This will help delay ejaculation. If there's no improvement then you must be investigated for any comorbidities like diabetes hypertension hypercholestrolemia. Treating these comorbidities also can delay ejaculation. Also any associated erectile dysfunction will also have to be treated. Medically there are many options like oral medications and topical creams. If the above conservative measure do not help kindly consult a psychiatrist for medical therapy. Please do not take any tablets on your own. Any associated co morbities can get aggregated because of it