Hi LC,
I'm glad to hear that your health is improving. It looks like you hate debt as much as I do. I'm happily FIRE, but 54 wasn't all that early. I did not marry until very late in life, so I like to encourage other single women in their quest.
I'm not positive, but it sounds like you don't have a lot of savings yet. The most crucial aspect of investing is time. Since you're playing catch-up, time is scarce. The sooner you start saving and investing, the better off you will be. I'd politely suggest that if the interest rate is low, you rethink your plans to pay off the car loan early. Instead, make your payments as scheduled, putting the excess into your own savings. While you're building up this savings, it can serve as your EF. Once you've accrued the payoff amount, you can decide whether to kill the loan with a single payment or continue to increase your savings, while making steady payments.
Debt is not always bad. It is also a tool for creating wealth. If you want to boost your retirement savings, start NOW, don't wait until the car is paid off. It's not the standard line, but thinking a little differently could make a substantial difference in your net worth, which is the real goal.