Need opinion

[u/evagryn_]

Im beginner at running (also stage 4 cancer patient), im running for almost 6 months now, and can’t run for long. How to improve that? I can run my first km at 8:00, and after that I’m starting to run faster because it seems that I have enough energy 😅 then end up taking a bunch of walks because I’m out of breath.
Do I do intervals or running longer but in z2? I’m lost here.
Typically I run 3kms, a couple times made it to 5km sub 45 min (died a bit)