I think research has shown you are not going to rid yourself of excess weight through the gym alone. Certainly a help in increasing metabolic rate provided your heart rate increases, but is probably more helpful in toning the body.
Realistically, you are going to have to cut the unhealthy snacks you are currently eating. Apples and bananas may get boring, but given the variety of fruit readily available in supermarkets (or prepared fruit salads, unless you mix your own), try experimenting with fruit you are unfamiliar with. There must be 20 fruits readily available to provide healthier options. (Separately, could breakfast, lunch be 'better' to help you through to you evening mea
Sorry if this seems a bit "nanny-state", but just trying to help you achieve your goals