I wasted six years of my life getting a PhD degree. What should I do, and how will I survive? I struggled with low self confidence throughout my bachelors, masters and PhD in chemical engineering. After spending two years in Masters and six years in getting a PhD degree, I am lost at what I can do with my life.

Initially, my plan was to be in academia. Though I love doing research, I don't see that as a possibility anymore.

I did not do well in my PhD. I have only two first-author journal publications in ~2.5 impact factor journals. I did not acquire significant skills. I am bad at programming, and I have a 3.7 GPA. I did not learn to drive or learn any foreign language. I did not improve my health or developed a new hobby. I even did not spend time on having a relationship. In short, I have done nothing over the past six years.

My PhD supervisor has given me a postdoc position. And I feel extremely inadequate. I feel that I won't be able to do anything after my postdoc year, and I will just be a burden and disappointment to my parents.

I am an international student living in the US.

I don't know what I should do. What should I do?
It looks to me like you did not do so badly as you think. Two publications and 3.7 GPA are not so bad. It might depend on the field, it might not be the best ever, but I have seen much worse. If your supervisor offered you a postdoc position after having you for 6 years as a PhD student, it means that they consider your work useful.

You might be suffering from impostor syndrome. Do read the question and the answers in that link and see if you identify.

If you are not sure now, you have plenty of time during your postdoc year to decide whether you want to continue in academia or get a job in industry. The pros and cons of both options have been discussed extensively, as a quick Google search for "industry vs academia" shows. I personally agree with this source.

And, in most cases, the answer to "I have wasted X years of my life because I did not do Y and Z" is "do not look at the past and do Y and Z now". Especially when, as  in your case, Y and Z can be done at any stage in your career life, such as learning languages, programming or driving.