You might want to look into consulting a fee-only financial planner - you have a short timeline, as do I (I'm mid-50s). Interview nearby fee-only planners, find one that you are comfortable with, discuss your current financial situation, get recommendations, and together develop a plan. Then move some of that cash into investments.
You've done a great job so far - you are debt-free except for mortgage, you have savings, and you have an income stream! Retirement may be closer than you think. At this point, your goals are to continue to add to your retirement funds along with conserving the principle. Many here are in the accumulation stage only, so their path may not be yours. Continue to read and research your options, then proceed with a plan that you are comfortable with.