Like many things, getting good at writing involves both a lot of reading (observing others who excel at their craft, and picking up on what makes their work stand out), and a lot of practice (whether "forced", e.g., at school, or on your own). Having a concrete understanding of where you feel lacking can help you focus on what to improve.
(For what it's worth, your writing here, at least, comes across as coherent, directed, spelled correctly, with good cadence and grammar — it sounds like you're probably looking for higher-level improvements; but I don't want to assume anything.)
It helps to know what you want to write about. In my class, we wrote short articles on the effect of the internet on economy and society (very long ago, pre-social media). The 4-month long period of writing articles, getting feedback, then writing more articles, getting more precise and actionable feedback ultimately got me to a better place.
My instructor nitpicked everything, as she should have. One of the red-ink sentences I remember from my very first graded work was:
"Why does your article have this tone? What were the unspoken assumptions you made when you wrote this? Put them at the top of the article so that the reader is not left to speculate". I always remember that because writing on social media works the exact opposite way!
Writing ~100 pages per semester in university also helped.
Publishing a book made me realize how bad my writing still is without editing.
My advice, is to write more and be systematic about how you think it is bad. Attempting to quantify that can be helpful: "I think my work is bad" is different from "2/3 friends who reviewed this draft were confused by my lack of headers".
Also maybe do an edit pass yourself before taking it to your wife. Waiting 24 hours and then editing can help a lot!
IMHO, our society suffers from missing this divergence on a grander scale: the people who are the best at conjugating verbs also think they deserve to have their take on the day's current events broadcast to tens of millions of people in our newspapers and online content farms. The result is largely beautifully written dreck that causes political calamity, and people end up trusting someone who says "bigly" to lead them.
Another way to put this first point of mine: the best NBA players don't make the best coaches, because they know how to move on the court in ways they can't put into words for lesser talented, younger athletes. Likewise, being an excellent writer doesn't automatically yield the empathy needed to get into the minds of less talented writers who need baseline concepts spelled out in multiple, concrete ways.
So for that reason, I wouldn't exclusively rely on whatever advice/feedback your wife is generous enough to give you (though what a great boon to be married to someone with a skillset you currently need to develop: I hope you cook well or something!)
Second, this post is exactly the right approach imho: gather as many different approaches as possible and keep trying each one on for size until you've run your own massive trial and error process and exhausted all free and cheaply available resources.
As for what I'd recommend as one of the many people commenting here: Try the Great Courses audiobook on the topic to hear what writers hear in their heads when they distinguish good sentences from bad ones: https://www.thegreatcourses.com/courses/building-great-sente... Try Stanley Fish's book about how successive sentences work together with one another: https://www.amazon.com/How-Write-Sentence-Read-One/dp/006184.... Try reading stuff you love and focusing in on one or two sentences and the parts of speech those authors use, then try to mirror that and slightly improve the next thing you write.
Good luck!
If were wanting to work on creative writing, then I recommend starting with stream of consciousness where you just write down anything and everything that comes into your head and see where it takes you. May not be an efficient way to improve your ability to write good reports though.
I find it very difficult to articulate complex ideas and write well. Communication is important in every aspect of my life and something that I'm very poor at.
---
As an aside, you might want a different first reader.
Laughing at your work isn't helpful criticism.
Good luck.
I should note, that the laughter is not discouraging, it's simply the way we interact.
I'd work on these aspects first, then move on to some suggestions in this thread.
Something that has worked for me is to keep a list of mistakes I made in the past, or improvements suggested to me. I use it as a form of checklist to go through before sending off a new document, to at least avoid mistakes I've made in the past.