I am curious as to how much of your portolio can be attributed to your stroke of good fortune (i.e. inheritance) vs. savings/investments on your part. No offense, but it appears to me that someone who would play with margin account and lose a million before realising it's time to stop, isn't the type of person who would have the needed financial discipline to accumulate a sizable nest egg in the first place.
Without proper financial discipline, or at least a self-awareness of one's (in)ability to invest properly, no amount of money is enough. I can personally cite two examples of people who came into substantial fortune and lost it.
I have a cousin who inherited $10 million a few years back, and rather than being happy and content, decided to go into an investment with a partner, hoping to really make it big, despite the fact that he had never displayed any financial acumen or even common sense, and knew nothing of the line of business he was getting into. He lost everything in 2 years.
Another cousin, who inherited $7 million from his father about 20 years ago, decided to get into buying/developing properties, even though he knew nothing of the business. Needless to say he ended up with a fraction of his money. He had always been profligate so the result really wasn't a surprise. At least his father had the foresight to leave the bulk of the money to his sibling, so that he couldn't blow it all.
As Dirty Harry puts it, a man's gotta know his limitations. Sadly for my two cousins, they didn't. Here's hoping you do better.