A semicolon is a complex beast:
- You don't use it when you want an idea to stand on its own. You use a full stop for that.
- You don't use it to tie two ideas closely together because if you did, you'd relate them with lighter punctuation like a comma.
- You use it to relate two ideas weakly; it strongly implies there's a relationship between the two conjoined ideas but leaves it to the reader to determine what that implied relationship is.
As a result, it's difficult to use semicolons frequently without also using a slightly opaque writing style. When you use a semicolon, the fact that it clearly relates two clauses together without giving a direct indication what the relationship is necessarily forces your reader to read in-between the lines.
If you look at the list I gave above, the second bullet point relates its two clauses explicitly with the word because, allowing you to immediately understand that the second clause is related to the first due to providing an explanation for the first clause. In the third bullet point, the semicolon implies exactly the same relationship, but you are forced to read more carefully in order to understand that. You have to understand the two clauses separately, my implied context for writing this answer, and the parallelism in the entire list before you can be sure you correctly understand how the two halves of the sentence relate. It's not much more work, but it is more work nevertheless.
This isn't necessarily a bad thing because sometimes, that more opaque writing style is what you want. It's important to keep in mind that for writing fiction in particular, though, part of what you need to accomplish is making the task of reading your work pleasant and enjoyable for your readers. You typically want to write using a style that makes the semantic meaning of your story jump off of the page, allowing the reader to spend their mental energy on more sophisticated levels of your writing, such as the subtext in dialog or the thematic implications of characters' decisions. And, if possible, you want your writing to have a musical or poetic quality to it such that it "sounds good" in the reader's head.
Typically, a semicolon works counter to both of those goals. If you force a reader to spend some time figuring out whether your semicolon in, "I wanted to kill her; she had done so much to me," means that the speaker wants to kill her because of or in spite of what she had done, that's more work the reader has to do before getting back to reading in-between the lines of your story proper. And if you're trying to write with a musical quality, then forcing the reader to grind to a halt to understand a semicolon correctly can interrupt the rhythm (unless you're trying to get a slower effect).
All in all, though, these are definitely things to keep in mind at the level of being nitpicky. I would much rather read a story filled with semicolons, even awkward ones, that has compelling characters and themes than read a disjointed story with spotless prose. And every writer has their own style. Some people will never have occasion to use semicolons; others, like myself, will use them on occasion. You seem to like them, so more power to you!
When you finish your first few drafts of your story, you'll reach the point where the most important considerations aren't the structure or strength of the story proper, which have already been vetted and are largely set in stone, but rather getting the nuance and tone of each passage just so. This is the best time to consider the ideas of making your reading easy to approach and musical, and this is when you can really think carefully about each individual use of a semicolon. Until then, it's probably best to enjoy the story yourself as you discover it in the first couple drafts and not worry too much about the fine details of your prose, which you will thoroughly rework anyway.