I remember when I ran my first 3 miles straight. It was a HUGE accomplishment!!
I often have people tell me that they would like to run but they just don't have the stamina. When I tell them that I used to say "run?! my body doesn't DO that" they laugh. When I tell them how I became a runner I can actually see them thinking "hmmmm... maybe I CAN become a runner". It's all those small steps that do it.
I literally started on the treamill running for 30 seconds then walking for a minute, repeat, and on and on. I just kept trying to increase my running and decrease my walking. It took a while but look at me now!!
So yeah this is huge! Keep up the good work. And don't worry about being slow. Heck look at me! 10 minute miles are flying for me. I like to say "I'm slow, I know. Get over it. I did"...