In order to understand time you have to let go of your precepts. That is, the ideas you already have about time.
You said:
"time as an illusion to measure rate of change. the past, future and present are all now."
There is a problem in that. These times are not 'now', because 'now' as a concept does not exist. Let'stry lookin at time a different way.
Picture a number line. 0 is in the middle, and to the right the numbers tic off 1, 2, 3, etc... To the left they go -1, -2, -3, etc...
When you look at this line you see all the numbers stretching out in both directions. You can see 'all' the numbers. Now if you were living on the number line, let's say at the number 0, you would look around you and you could see the numbers 1 & -1, but you couldn't see all the way down the line to like 10 or 20.
So time is sort of like that. You live on the timeline so it is difficult to picture it. You are actually travelling down the line at a certain speed. It just so happens that you are traveling down the line at the same speed as everything else around you. If you were accelerating you would see time differently. If you weren't in the 'timeline' you might see that time doesn't 'go by' it (supposedly) just exists like our number line we were talking about before. The fact is that we are living on the timeline and we can only see just ahead and just behind.
I hope that helps...