I'm trying but...

Last time I went to the OB he said if I wanna make it easier to get pregnant I need to get my weight down, now I don't like people knowing my weight but fuck it... I'm at 336 right now it was slowly going down for two n a half weeks but it shot right back up and idk wat else to do I have tried many different diets and charting and tracking I start to see a difference n then it all disappears, I try to push past it and keep up my work to see if it will go back down n after a week or so of it not going down n still going back up I get really depressed and I quit I feel like I'm just on a horrible roller coaster