I applaud you for your honesty.Seriously if I made a big multimillion dollar fortune trading, why tf would I run a business.
Instead, I leverage by trading small, then teaching lessons learned from stops vs wins.
I applaud you for your honesty.
But I think with trading, there are many steps to master before you make it. Taking money out of the equation is one of the last few where trading just become a function of trade size vs. account size. This of course takes into account probabilities and all that jazz, but in the end, it all comes down to math. Simply put, if you give a proficient trader a 100k account he will more than likely be able to trade it the same as a 1 million dollar account. Once the fear of loss is gone, it all just comes down to percentages and grinding it out and taking your setups.
In your case, it sounds like you're still struggling with this last step. I'm not say everyone can overcome it, but this means that you are only able to teach certain aspects of trading, but the all important psychological aspect eludes you as well. Its certainly the hardest aspect I think.
If you know what you're doing, if you have traded through all market conditions, if you know that you will always act in your best interests, then the size to trade is simply a function of account size. I guy with 5k can maybe trade 1 micro ES proficiently. If he had 25k, then he could do 5 MES. Likewise, a 500k account should have him trading 10 ES. Granted, many when they start scaling up start to trade it differently, and often times this is where problems arise, but the proficient trader understands it all comes down to math and percentages.
You certainly get into liquidity constraints. ES isn't as thick as it used to be. The size posted at each BID and ASK isn't the same as years ago, and I think the volume is a bit down as well. If you need to buy 100 contracts at one price level, it might be possible, but looking at volumes over 5 seconds as an example, you might be moving the market. But of course if you're going to lets say accumulate 1000 contracts over several minutes, no issue at all I would say."If he had 25k, then he could do 5 MES. Likewise, a 500k account should have him trading 10 ES."
How about a 500M account?
Lol... that's for a small entry for a swing trade.... perfect entry. fwiw that illustrates my biggest failure is I trade too small.... so I leverage skills as a publisher.
Same thing in poker, I played small tournaments, even winning one, but I stay small stakes #growapair
In trading there's lots of ways to make it, or miss it. I like both swing and daytrading, and position sizing. Being a good technical daytrader doesn't mean you also gain the mental nerve to trade large size, much to my disappointment.
It is because you were not listening to the right music. That's an important step.
Glad you got it figured out, and the pain in your nexk went away.
There are a lot of moving parts to a day trading strategy. 

You certainly get into liquidity constraints. ES isn't as thick as it used to be.
I am in vacation these days...I still remember when there were +3,000,000 contracts a day traded....