Crutchlow's 2017 campaign got off to an inauspicious start when his Honda let out a significant oil plume on the run to Turn 1 on his first flying lap.
The Briton said the cause of the oil leak was being investigated, but admitted it affected the rest of his session, after changing bikes and oil-soaked boots.
"I nearly high-sided going into Turn 1, at fucking 330km/h [205mph]," he said.
"Honestly, for the rest of the session I rode shit, really scared, really shit.
"When you have something like that happen, it takes a while to get over.
"If you crash, and you know why you've crashed, then you say, 'OK, I crashed a lap ago, I'm on my spare bike I can go faster, because I know why I crashed'.
"With that, and it's not in your control, you're shitting yourself the whole time.
"It turned out - OK, I was riding bad - but the lap time was not too bad considering and I was on a bike we'd never ridden before, setting-wise.
"It was just going to be doing two laps today and I ended up doing the whole session [on it]."
Crutchlow finished with the seventh-fastest time, 1.323 seconds off the pace set by Yamaha recruit Maverick Vinales.
Thursday practice report: Vinales starts season on top
He was one of three Hondas in the top 10, with factory pair Marc Marquez and Dani Pedrosa second and third, the only riders to get within a second of Vinales's benchmark.
Honda has introduced an all-new engine with a different firing order for 2017, in a bid to erase its acceleration deficit, and Crutchlow is encouraged despite the fact the electronics are still yet to be "figured out".
"We're all still getting used to it, because it's something completely different," he said.
"It's better in some areas and worse in some areas.
"But this is a complete first time of trying it and doing it, and it's not bad, because the lap times are competitive.
"I think Honda will figure it out in the end, it's just a matter of giving them a bit more time - especially with this configuration of engine."
Read the original article on Eurosport: Crutchlow rode 'scared' after early problem