3...d6 is the variation Fischer proposed after his loss to Spassky... the OP didn't play it as well as Fischer, but I don't really think that matters
About 1985 or so, I followed Fischer's advice in his little pamphlet in a USCF postal chess game and got creamed. I don't trust his analysis. Too short and glib to be of much use.
There was a saying at the OTB club where I played casual games. Something like "but he's Fischer and you're not." It may have been an old quote but I don't know.
Essentially any time someone tried to excuse a move by "I know it looks crazy, but I saw [insert GM name here] play this move, the response was "but he's _____ and you're not."
In other words, it might be a good move, but you obviously don't understand why it's a good move, so it's the same as playing a bad move
Pretty much sums it up. Sums up most amateur chess in fact.
You might want to look at the Falkbeer Counter Gambit: 2...d5. After 3. exd5, Black has several interesting continuations.