Getting serious now...

Not really serious, just serious about the exercise. For some absolutely bizarre reason, I was awake this morning at 7:30 a.m. Why???? I don't have class until 11:30 (if I choose to go, which I just may not, it's damn freezing out!!!) and I don't go to the gym in the morning. But, here I was at 8 a.m. trekking to the gym. I figured, what the hell, I might as well go while I'm up, before I have the whole day to formulate an excuse for not going. I sent a thread on 3fatchicks.com asking if anyone ran, and if they did, how they started doing it and I got a bunch of replies back telling me to go to the coolrunning website, so I did, and signed up for their couch to 5K program. It's supposed to get you running three miles in 9 ish weeks. I went today for my first workout. Holy hell. I am so out of shape it's not even funny. Ever since Sunday when I went to the batting cages with my boyfriend, my back feels like it wants to snap in half. While I know that being sore is good (not pain sore, just sore)it's a bitch to get through. But, I really want to run. It seems like people that run definitely have better bodies, and I want a better body so...Seems obvious right? I weighed in yesterday at WW and I lost 5.2 pounds! Yay me! I tend to do very well on WW because I don't like the idea of someone telling me that I gained weight, so I really pay attention to my diet. I do know that it happens on WW sometimes. I just need to figure out WHY I stop going to the Weight ins. I do so well, but then one day, I just decide, I'm not going to go this week, I'll go next week, and before I know it, it's 4 weeks later and I've gained some weight and I don't wanna go weigh in now and everything spirals out of control. I need to nip that in the bud NOW. Any suggestions??