Help

I am 27, 5ft 4 and weigh 14st......I am not happy with this...... I try many different diets including tablets from doctors, slimming world, slimming patches, Slimfast, 5:2 and nothing seems to shift....all of these diets have been tested over a period of a month + without losing a pound. I used to go the gym an hour a day......burning at least 800 a time without any change, I did this for a year!!!. I wonder if anyone can help in giviing some advice on were to move next. Is this just the way i'm supposed to be or is something seriously amiss?