Ideas about foods and exercises for lowering cholesterol and tryglicerides as well as lose weight

Besides regular meals, I tend to eat when I'm stressed, bored and for comfort. I want to change those habits. I had a weight problem years ago and found that with the right foods and exercise, my "cravings" stopped completely and I was able to remain on a healthy diet and lose weight and kept it off for several years. Personal, family issues caused my stress levels to go back up. I was taking care of an elderly parent who had alzheimer's for about a year and a half to two years. Inevitably, I had to place her in a nursing facility where she died 8 months later. As a result, I became very depressed and felt guilty about her death, blaming myself, thinking if I had kept her with me, she would have lived longer. I started eating poorly and too often. I became sendentary and put a lot of the weight back on. Not all of it. I had weighed 220 lbs before that and I top out at about 171. But I'm 5'3" and small boned, so it's definitely not a healthy weight. Anyway, I need some ideas of exercising and eating right. I'm in my 50's now and I've read that people over 50 need to do different kind of exercising. I do the standard aerobics, firming and treadmill. But I wonder if it's enough. I'm looking for support from others who may be experiencing even a little of what I'm living with right now.