Opinion Anybody?

I need somemore views on this little part of my life called parent hood. So most of you know that our first pregnancy didnt go very well but the outcome was amazing. We have been wanting more children but i cant seem to overcome this fear of it repeating again. The doctors have absolutley no idea why this happened and cant give any other reason than it could have been the fact that i was overwight(do keep in mind that all my labs that far were good). The fact that i was diagnosed with PCOS there shortly after i had Caden. And they say it could be a fluke thing and may not happen again. Now the statisics are if your first is preme then you have a 25% to 50% chance of it happening again. They also say that pre term birth isn't hereditary but my mother had all three of her kids early.(just some things to keep in mind)

A little over a year ago i went to my gyn and was dicussing all of this with her and she says that i shouldn't feel guilty and shouldn't be so reserved about all of it but it is so hard for me to picture such an innocent precious thing having to go through the torture that Caden had to to survive. Its really sad and can be very hard on the child and us as the parents. Anyways She told me that first lets try to drop some weight. So i took it very seriously and dropped 68 lbs but when i went back to the doc she said i should drop 30 more lbs. Grrr! This was in aug and i have not been able to cut anymore wieght it is so frustrating. All i want is to have a baby but dont want to have the guilt on me that "if i would have just dropped that thirty more lbs this may not have happend". Do you know what i mean? I am going to be 28 this year and have that working against me as well. I am already high risk and the closer i get to thirty the more high risk i become. Caden wasnt a planned only child i feel terible hes had to go this long living as an only child, but not sure what to do. So; I guess I would just like some more opinions on this and see what differnt views I can get. I apologize if this comes off as complaining but this is something Jamie and I have struggled with for years now and i just dont know how to overcome these fears. Not sure that you guys can help that but thought it was worth a try. Thanks for any advice or opinions.