"I can't do interval training because if I stop to walk I won't be able to start running again."
The entire time I was training for that Marathon I kept thinking, "If I stop I won't start again." I practiced drinking water while running, taking on and off layers while running, not peeing for 4 hours... all on the assumption that slowing down or stopping would mean I had failed.
God, that was such a mind f*ck.
I'm learning so much going through this C25K program. The most important thing: take a break. You'll do much better after 60 seconds of catching your breath than if you try to gut out the next 25 minutes without it.
A crazy man once told me to live like a wave crashes on the beach. Waves don't always swell- sometimes they recede. It's ok to recede. It'll make the swell that much sweeter.