You have some good ideas, skillfully orchestrated.
Perhaps you have enough material for a piece of no more than half its current length, at most. Each section goes on too long. And each section now has its own slow start and build, which is too much. I would commit fully to each variation right off the bat. Maybe what you need is more variations, each one shorter.
The opening, for example, repeats too much. It needs a simple statement to stick in the mind and then go zoom, into the first variation. And that first variation can better make itself felt dramatically by contrasting it more with the original theme.
Do you have favorite variations by other composers? Mine are the Brahms Haydn Variations and Benjamin Britten's Young Person's Guide to the Orchestra. They're each about the same length as yours, but Brahms has eight variations and Britten thirteen.
Can you post a score? It's always easier to comment when one can see the notation.
Cheers,
Jer