advice welcome xx

hi... I would just luke sone advice on a few things if anyone could help?? im currently 14 dpo got my bfp on 9dpo.... I have been smoking everyday for the first two weeks of my pregnancy I have quit today but wonderd if I may have already caused damage to my little one to be...?? also I am a keen runner and go to the gym on the treadmill daily am I still ok to do this or is this harmfull?? also what kind of foods should I be eating and how can I stop stressing about weather my baby is going to make it past the hard part or something maybe wrong with it??? im so glad I got my bfp and just stressing so much that it will all be ok and run smoothly any advice would be greatly appreciated xx