An unfinished love sonnet for R&J

Continuing my mission to do at least some of the same work that I ask my students to do (I figure that within a year or two of teaching I ought to have managed to write up exemplars of it all), I started working on a Shakespearian sonnet for my year ten class. I started working on it while at that training seminar I went to two weeks back, but haven't really done much with it since. It's almost done--the third stanza's a mess, and that's what I haven't finished yet. Any suggestions?

A Love Sonnet for R&J

When I think of you my mind’s eye sees ice
Unyielding, rigid and bright, strong and cold.
Unthawing such a love comes at a price
Too heavy to bear, or so I’ve been told.

But cold can burn as strongly as the sun
And captured light in hoary form does shine
Brighter than light unconfined. Do not shun
This inconstant star, this brilliance of mine.

[If lonely passion seems too weak to melt]
or
[My love may not burn strong enough to melt
Passions spent too quickly may not touch deep
Yet last long. Caught in glass they may be felt]

Separate things in frozen form become one;
Caught in you my love be forever done.

Meh. So some bits weaker than the rest, but overall not too shabby, I think. Well, fine... but it's still a hell of a lot better than my Villanelle!