Hi and welcome
Just a few things that come to mind
* You say low fat - roughly how many grams of fat a day? You may not be eating ENOUGH fat. Sounds crazy I know, but eating to few grams of fat can result in your body clinging onto the existing fat. Also, many low fat foods are packed with sugar (carbs) which can very much be the cause of no loss.
* How much protein are you eating? Not enough protein can also result in little to no loss
* Are you tracking calories? If not, a great site is www.calorieking.com.au
it is free, easy to use and you'd be very surprised how the calories really sneak up.
* How many meals are you having a day and are you eating close to bed time?
* Are you drinking at least 2 litres of water a day?
Exercise definitely plays a big part and also allows you to eat more. Find something that you actually enjoy doing, that way exercise becomes fun and not a chore. I personally hate walking and bike riding (including stationary) so I never ever do those things. Things I love are horse riding, cross fit, weights, skipping, martial arts classes so I only ever do the things I want to. If I wake up one day and feel like doing nothing but skipping, then that's all I do. You have to make it enjoyable or it just won't work long term.