"will increasing exercise and reducing fatty foods help me bring my numbers back to normal? " Yes!!
Exercise will, not only, help bring your blood levels back to normal, it will also help rebuild muscle that may have been lost while sitting at the computer. It really is true that we have "use or lose it". If we don't use our muscles, we will experience muscle wasting.
Also, cutting back on fatty foods - will contribute to better cholesterol levels and help bring them back into line. It's the things like chips, crackers, cookies and candy that cause us to gain weight, especially without enough exercise.
So - how drastic do your lifestyle changes have to be? That depends on you and what you you have in mind for your body. I find that it's always good to start slowly because if we try to change too drastically, there's a good chance we might not be able to sustain those changes.
So you could start out by setting a alarm on your phone to remind you to get up and move around for at least 5-10 minutes/hour. It would be good if that could include going outside and going for a short walk, but if it can't, just walk away from the computer and do some walking in place, stretches or other exercise. Another simple thing is to replace a handful of chips (or cookies, crackers, etc) with an apple or keep some hard boiled eggs in the fridge and have an egg instead of snacks. Replace sodas with a glass of water. If you, typically, drink several sodas/day, start out by replacing 1 of them with water. A couple days later, replace another soda with water - keep doing that until water is your drink of choice.
I don't know what your meals are like, but try to make sure you have some protein with every meal/snack you have. That can be meat, eggs, cheese, peanut butter (be careful with nut butters because while they're good for you, they also contain a lot of fat).
Between adding a few minutes of exercise several times/day and limiting or eliminating fatty snacks, you'd be surprised at how quickly you can get healthier.
You can check YouTube for a variety of quick exercise you can do, but walking is always an excellent form of exercise, as are exercises that use body weight.