DDH - I don't have a lot of advice to add. All the others here have told you a lot... good shoes, form, more calories... But I did want to send out my support. Starting a running program is hard and good on you for having the guts to try.

And I wanted to share this story...

I knew a lady who in her early 60's was trying to catch her bus and wasn't able to run to get there on time. She was a nurse and was overweight. She became upset with herself for allowing her body to get so out of shape. So she started to walk. Then she added in short runs... "Maybe today I can run from this lamp post to the next one"... and she just kept adding lamp posts. She ran her first marathon when she turned 70.

You really can do this.