Is my eating habbits bad?

Heya, im 22 years old male and have a full time job and basically i think im getting a little fat lol, i weigh 14 stone 3 and im classed as obese everyone says im putting on weight, but i dont get it because all this is my daily food intake, Morning i have cereal usually corn flake or tesco fruit and fibre with milk, and i have a coffe with 2 sugars, lunch time, i have 2 pieces of bread with ham and butter as a sandwhich which a bag of crisps and a small chocolate bar usually a penguin bar lol and a coffe with 2 sugars, for tea it varies everyday depening on what my mum cooks, i only have akeaways once a month, usually a dominos or a McDonalds and i someimes have a the odd chocolate dair milk i never drink fizzy drinks, what should i do to get my weight down, im always on my feet and active at work ror 8 hours i work in retail so im constranly walking around so that really is my only excersise so what am i doing wrong what should i do