Honestly, I was going to recommend what you're doing now, except with the addition of possibly learning LaTex at some point for the more complicated math.
Good luck!

If you're comfortable with what you're using, I'd stick with that, which incidentally is what I would choose in your situation. Personally, I decided to learn LaTeX on my own time and write maths in that, using tools like Pandoc to convert my LaTeX infused markdown documents to .docx files. But that's one heck of a lot of effort to go to, and I really only did so because it's free and I'm a computer nerd who prefers to use macOS or Linux, on which Word and MathType aren't available in an accessible form.