Am I kidding myself that my current habits are enough to get results?

A little background: Around 30 years old. I'm 5'11'', 260lbs. I have an unusually teardrop-like body shape for a guy - wide hips and legs. I've been 220-280lbs my whole adult life. I'm looking to drop some weight and gain some fitness, and I'm wondering if I'm doing enough to eventually see some weight start to drop off me. Here's the basics:

Exercise: Gym approx. 4x a week. First I do 15min on the elliptical, slowly raise the level, pulse goes up to about 170 (I'm out of shape, obviously). Then I alternate days for Chest, Shoulders, Back, Leg Push, and Other Legs/Micellanious. After, I'll do various stomach exercises most every time.

Typical Chest workout: Bench: 95lbs x12, 115lbs x8, 135lbs x4-5 Peck Machine: Same idea, 4 sets, 85-150lbs 45deg. Incline bench: Same idea, 3 sets, 50-80lbs(seem to suck at this. Shoulders are not great either) Dip assist: 2-3 sets Pullover: 3 sets Chest press: Whatever I have left

Typical Leg Push workout: Squat assist - 180lbs x 12, 240lbs x 12, 300lbs x6-7 Leg sled - Same idea, 3 sets, 160-240lbs Leg press - 3 sets, 200-300lbs 'Leg day' KILLS my stamina. My muscles can handle the weight, but I get physically exhausted.

On days I don't get to the gym, I'll at least try go for a 2mi or so walk, alternating some running (at this point I can only run for 1/4 mile spurts before I have to stop). I also try to keep up with stretching and doing abdominal stuff.

Diet: Um...not great. Usually wait 2-3hrs after waking up for first food. Then I wait until diner to eat again, and have a big meal. I love Japanese sashimi, but more often it'll be Cheeseburger, 5pc Chicken Nugget, and sm. fries from whatever fast food place.

Drink lots of water, sometimes 1% milk. Never drink soda/fruit juice. Never remember to take vitamins. Will go through phases on eating dessert items - one week splurging and another week abstaining.

I started committing to the workouts almost a month ago. Since then, my weight has gone form 260 to...260. Am I eventually going to start dropping some weight, of do I need to step it up on diet and/or cardio and fat burning exercises? Any other advice as well would be great. Thanks.