My best advice would be that you need to look at your writing through a reader’s eyes after you’ve finished writing it.
Question all the examples of figurative language. Would a reader, who is totally unaware of your thought process and cannot jump inside your head to see the connections between figurative language and a larger theme, understand what you’re trying to convey?
If the answer to that question is no or you are unsure, then try making the symbolism or comparison more obvious and clear. Choose the sentence containing confusing figurative language and revise it to make it simpler and more straightforward, but still not cliché.
Once you’ve revised all the confusing pieces of figurative language, step back and look through the reader’s eyes again. Are they less confusing and more to the point now? Can the reader make connections between the use of figurative language and the larger theme now?
If yes, that’s great! You’re done.
If no, either revise more, or actually get someone else to read your examples of figurative language. If they still can’t get it with the revised version, then ask them for suggestions on how to make the examples clearer. (You can also ask someone to read your examples at the very beginning too, before you even start revising them.)
You can also try some online resources that might help you write clearer examples of figurative language, like this website:
http://www.creativejuicesbooks.com/figurative-language.html
I hope that helped! Best of luck c: