I'd trace the source of our problems to slightly before he was ruled out for the season. The Valentine's Day game against Grays was a huge turning point as it marked the start of Williams' only dip in form all season.
The next game was the massive match against Burton, which Williams failed to influence, he was rested for the FA Trophy game against Ebbsfleet and then didn't have much of a chance in the replay, and in our next game he was injured.
So the goals actually dried up when a tired Williams stopped leading the line to his usual high standard, his injury merely compounded the problem.
Whether his fatigue contributed to the injury is not something I'm qualified to speculate upon, but if it's a possibility, it shows us that we can't expect Williams to run himself into the ground for the cause again next season. Equally, our plummetting form shows that we must recruit enough quality in the Summer to ensure the loss of one man can't lead to such catastrophe again.