You are doing so well. Especially congrats with all the exercise you are managing to do. Really happy for you - not just in terms of weight loss, but also the sense of achievement you must have.
I personally think flexi syns are fine, especially if it's worked for you before. Everybody is different, but knowing you can have a takeaway on a Friday night (or however you use your syns) can be really motivating the rest of the week.
In entirely unrelated news, have you ever watched Bitten? 2 seasons are now on Netflix - it's based on books, and about werewolves. A little melodramatic like Vampire Diaries, but more nudity and generally more adult story lines.