1st Week of Running

One of my life goals is to run a marathon, however I am a bit of a big girl, I'm currently hovering around 200lbs. So that I can meet that goal, and also because there is a wedding in the family coming up, I've gone to a dietitian who's helping me with my bad eating habits  and I'm getting weighed, right now, every two weeks, and I've started running. Now since I've never run like this before I'm not just going out & running until I pass out I'm doing it with this great article couch to 5k. My aunt used the same program when she starting running a few years ago, and she's in her 50's, I'm in my early 30's. I started Monday, the 1st few little runs were really hard and I lost my breath easily. Tuesday I hurt everywhere, I really do mean everywhere. I didn't go for a Wednesday, I went out on Wednesday (To see where I went check it out here), so Thursday was my next run day. Thursday it was much easier to run & even right after the run I didn't hurt, Friday I didn't hurt either. Today I ran again, I was with my aunt, who had walking sticks, and my mom, who was walking my brother's dog, who thinks he's still a puppy. Every time I would start to run the dog would try to run after me & because he's kind of big he would almost drag my mom with him. Again it was a little bit easier & because it was cold outside I wore a sweater, which I had to take off for a bit. Now though for some reason my arm hurts, that might not be because of the running though. After the run, I had a shower, had a salad, & then took a nap, I was so tired. From this 1st week of running I'm hopeful for next week. I just have a few notes for myself, 1 ALWAYS remember to stretch, I've really got to get that through my head, I forgot the first day so I'm not surprised that I hurt so much on Tuesday. 2 Make sure there is enough water for the whole run, Monday I ran out & that sucked. 3 Invest in a new sports bra soon. I'm poor right now and I'm using an old sports bra I got a few years ago, I have rather large breasts (DDD) and they bounce around a little more than I would like. 4 Look up runners diets & talk to my dietitian about them. Right now I've added more  vegetables to my diet and I've heard that runners usually have a heavy protean diet, I want to make sure I'm doing it right so that it doesn't bite me in the ass later.