If its possible you are probably gona want to start over. that flimsy stem isnt going to hold any keepable size bud and its far to late to bulk it up. A couple suggestions would be use a fan next time, if it is possible get a hps or metal halide even if its just a 15o watt- you will definitely triple your harvest atleast, stretching can start during the first week of growth so if your using a fluorescent keep it like 4-8 inches away, use good soil fox farms ect- good until you learn how to test ph and are familiar with nutrients, dont overwater- no more than once every four days,. temp should be around 75 degrees atleast and the space between each internoede should be no more than an inch - an inch and a half. Not much but it should help