First I would ask you to do some self-introspection and ask yourself whether your conclusion that you are 30 lbs overweight is a sound and realistic conclusion. As you get older you tend to gain weight. And although we are told that being thin is healthier as you get older actually you have better health if you are not rail thin.
That being said I don’t have any information on you. I would tell you that a female that is 40 years old, is 5’3" and weighs 130 lbs has a BMR of 1330 calories. Since you say you exercise every day, even conservatively as “moderately active” you would then multiply that BMR by 1.55. That means that you need 2000 calories a day. If you have been eating 1200 calories a day your body has probably concluded you are starving and is essentially fighting everything you do and trying keep all your bodyfat and keep you alive.
Second, there are medications that for some people help with weight loss. Metformin can help by making you more insulin sensitive. The GLP-1 drugs (Byetta, Victoza, Bydureon, etc) also help some.
My recommendation would be first to get your head around being healthy and then working on your body fitness. Instead of focusing on weight, focus on reducing body fat. And most of all consider a diet regime that provides sufficient energy and let’s your metabolism return to normal.
ps. With the SGLT2 drugs like Invokana it is vital to stay hydrated, not just drinking water but maintaining electrolyte levels. My opinion is that many euglycemic DKA cases with the SGLT2 drugs are due to the failure to remind patients to avoid dehydration.