Need help with basic writing skill to pursue my dream career?

I want to be an attorney, but I have  shied away from going to law school, because I am not that great of a writer. You know the people who say, I can swim enough to save myself, or I took that class but survived it, that is me. I went to an inner city school, and when I got to 12th grade, a wealthy man gave all the students a scholarship to go to college. I was awarded a scholarship, but essay writing was not introduced until 12 grade. My last month we were just learning summary, plot, main ideal, and thesis. I went to KU.  I struggled, because I was not a good writer. I could not get papers in by the deadline, because I was just writing papers out the sky. I had no format.I graduated   Some basic fundamentals of writing, I just did not know. Through the years, my kids have had personal injury cases, and other family members have had cases, and I have always been told that I should be an attorney, by other well know attorneys with big companies. I have actually help them find evidence, arguments, and case studies that have helped them win their cases or increased the value of their cases. I do not think I have a disability in writing. I just feel I need to go back to the most fundamental things, and also learn essay writing, to feel stronger in my writing. How do I go about doing that? I already have a degree, but I managed to get through my English classes with a passing grade, but I really want to become confident in my writing skills to pursue a law degree.