I've already belabored the point enough, but what happened at Edgebaston you get once in god knows how long. And despite all that, we blew it in the last test, rather than England winning it. In the last 20 years of watching Australia I only remember once, at home, I think it was either against England or South Africa in the late 00s or early 2010s, where we genuinely defied the odds to win a match in the 4th innings.
In cricket, lightning most certainly doesn't strike twice. Obviously, it'll help if we can get the 70 runs to hit 300, but even then, I'd still be confident we'll win with anything above 250. I just don't see any reason to panic about the situation or think that it won't result in us winning. History would back me up.