You all seem to miss and gloss over the most significant "stress" of all, which seemingly also could have played into his demise;
The pressure of the Triads that were after him. This should NOT be taken for granted. Bruce Lee's personality type in HK was very rare. He was absolutely defiant against the organization, even to the point of "well kill me, then."
It was why his family sent him away in 1959. He'd rubbed someone influencial the wrong way and was going to pay-dearly. You don't think it repeated itself in 1972-73? Then you are foolish. And what happened with Brandon? "Revenge," it has been said, "is a dish, best served when its, old... and cold."
With all the mishaps, false info, and nebulous reports around this man's death, it's painfully obvious, a cover-up was implemented. People have bought it, hook, line, and sinker.
Jackie Chan almost met the same fate but had the humility to align himself with authority that could assist in dealing with these issues, and enjoyed a long, stable, career. Bruce was too defiantly arrogant to do so. He destroyed himself.
When you play The Game, it's undoubtedly controlled by those who've 'made the rules', and sometimes you may win, but it's designed for you to lose.