New! Got any workout tips for an injured ultrarunner?

Hi! I'm so happy to have found this site through YouTube.

I'm a runner who hates strength training, and therefore never does it. In retrospect, this likely contributed to my achilles giving out 80 miles in to a 100 mile race. While it heals, I figured I should start establishing a strength training routine, so I can better prep my body to handle the impact of hours upon hours of running. For now I want to focus on my upper body and core (I'll add lower body in when I can move around comfortably and without risk of further injuring my foot).

Can anyone recommend their favorite videos? Particularly any that would be more beneficial to running? There are so many to choose from, it's all a bit confusing. Thanks in advance for your suggestions!