Am I mentally ill? or Is sales in large corp just illusionary?

Q:   Is sales in large corp is just illusionary version of entrepreneurship?

Context:

1.) I worked in startups for the thrill and learning across multiple roles. Earned some money, and alot of courage & self-esteem.

2.) I then co-founded a software startup that failed - Lost the money but still learned hell lot about unpredictable world and dangerously courageous to navigate it.

3.) Got myself back into corporate workforce in large corp - to earn the top dollars back and stablize the family with kids but the people I am surrounded with are crushing my soul, I am losing the courage and declining self confidence.

Realization:

Large corps have so much money and resources wasted on useless things that one can make sufficient money by exploiting their habit of spending big money irrationally. The worse is that their end customers (who are also large corps) are equally willing to spend stupid money with them due to lack of courage in their leaderships. But working in environments like this is soul sucking - I am Individual Contributor hitting about 100% quota for last 2 years, so earning back the $$$ I needed but losing the self-esteem and feel like shit - surrounded by too many managers and colleagues who don't inspire the fire in me.

Problem:

Is this a normal processes of taming the wild for becoming a good but lifeless corporate citizen? or Have I lost my mind?

How do you cope with this?