Does this sentence make proper use of the semicolon and colon?

There's nothing awkward about it. It's stylistically somewhat extravagant, but there's nothing wrong with that. It's crystal clear. Some people may stumble momentarily on the use of ellipsis in the latter portion, but it's nothing to get worked up about.

I believe the usage is all correct, but even with your explanation, I had to read it several times to understand the construction.

It is correct, but could have been put in a clearer way using commas,:

Relationships once so convoluted and beyond me were now clear: Pain become love, betrayal became loyalty, nonchalance became care.

If you're writing, the above would have conveyed your meaning better, but if you're speaking, your own example is the best.