D.B.
Welcome to Mamapedia.
No, it's not too late to get a handle on this. I work with a lot of people with sugar issues - diabetics and hypoglycemics, as well as people with food sensitivities. Hypoglycemia and diabetes are different things. Metabolic syndrome is a precursor to diabetes - it includes high cholesterol, high triglycerides, glucose tolerance/processing issues, overweight (especially around the middle), and other factors.
You're already identified the problem: weight, inactivity, a heavy dependence on sugary junk foods and soda. You're certainly going through sugar "crash" issues, but whether or not you have hypoglycemia, we can't say. A hereditary issue is not irreversible - the science of epigenetics is teaching us a lot about changes in the expression of our DNA (sort of like turning a light switch on and off) - it's not embedded in the DNA and it absolutely CAN be influenced by stress, environmental factors, nutrition and disease. I just read two articles this week about the role of exercise and the role of trauma in affecting gene expression.
So you're not stuck with it, but you have to stop "treating" it with a spoonful of sugar! All your sugar intake is giving you a "high" followed by a 'crash". It's a very unhealthy cycle. Some people get a similar effect from caffeine - the withdrawal gives them a headache, which is relieved by more caffeine.
Start making healthy choices - get rid of the Coke (and don't switch to Diet Coke!), start making your own healthy snacks, and include more protein. Don't cut out fats - but do switch to healthy fats like olive oil, nuts & nut butters, avocados, peanuts. Having a piece of fruit is far superior to sugar. Add cinnamon to fruit or yogurt - it tastes like a treat but it's not harmful and also has some benefits. DO snack so you don't get starving, but snacks are things like a few slices of apple and about 15 almonds. Keep these at your desk.
You have plenty of opportunity to exercise even with a sedentary job. Park as far from the office as possible, and walk. Take the stairs. Park far from the grocery store or dry cleaners. Go outside and take a brisk walk if the weather is good. If the weather is bad, go to the mail on the weekends, and just walk - they open early for walkers, hours before the stores open. Get a $10 pedometer and count your steps. Your goal is 10,000 a day, but start with 2,000 and work up. You'll feel better and you'll lose your food cravings.
Get a light set of weights - maybe 4 and 8 pounds. Stand up while you watch TV, and do biceps curls and shoulder presses. If you don't have weights, repurpose a couple of 1 liter soda bottles filled with water, and hold them in the middle as you do arm exercises. Hold on to the back of a chair or get down on all fours, stick the weight behind your knee (gripping it with your bend leg), and do leg lifts to the rear and to the side (called "hydrants", like a dog lifting his leg). Get a couple of workout DVDs from the library and watch them so you learn the proper form for protecting your back and neck (2 of the most common areas for injuries especially when starting out). Weight training is good for muscle development, and muscle burns more calories. It also helps ward off osteoporosis.
Make serious changes but in small increments - every little bit helps. You can join a gym for about $20 a month - lots of specials going on at this time of year. Be sure it's a gym that is open a lot of hours, and not one just populated by "muscle men" - you want other people like you. Find a class for beginners that is very supportive. You can go before work, after work, on weekends. You can walk on a treadmill. You don't have to hire a personal trainer, but do get the staff to show you how to use some of the basic machines for weight work - that's free in every gym. Start slowly so you don't get injured and discouraged. Keep the weights light and the number of repetitions-per-set reasonable, like 10-12 only.
Everyone needs nutritional supplementation, but there are a lot of money-wasters out there that do nothing. Don't take something with just a few vitamins or minerals in it - that's not how your body utilizes nutrients. I work with people on this all the time, and you'd be surprised how fast your health, energy, sugar level, cholesterol and mood can turn around if you do it right.