Sorry to hear about your head injury.
Have you checked the width of your jelly rolls? If they are not all the
same width they might not match. I also like to heavily starch my
jelly rolls. When working with bias edges starch is a big help.
Even if it doesn't match perfectly, it won't show after you quilt it.
If it gives you too much grief, move to something else less stressful.
Just have fun.