While exercise is important for heart health if you're a sedentary person who basically only moves when you formally exercise, I will repeat, long-term studies that have been going on for decades of actual living humans in various communities around the world do not find formal exercise to be important to long life or healthy life. But you know, those of us who grow up in the US don't really learn how much harm our parents caused us until we're adults, so for Americans, it's probably more important to exercise than it is for those in other developed countries who have healthier populations. But what research does show is that movement rather than formal exercise is what's important, and that it's very hard to make up for days of sitting at a desk or in front of a TV or cellphone by exercising a bit each day. So the societies that have been studied usually still follow a lifestyle that includes little driving and a lot of walking and bike riding to get around. It involves not eating very much red meat. Most importantly probably, it includes a lot of colored veggies that have the antioxidants that protect the heart from damage. I'm guessing, Mom, that because you're raising two kids, you probably do a lot more moving around than someone who doesn't have that job, so maybe you're judging yourself a bit too harshly as to the amount of movement you're getting. But you're also someone who is used to exercising, and so your body is used to that as well, so I'd say for you it's probably a good idea to just make the time you need for it. I think I've shortened my life considerably in the last year because I've already got two strikes against me in that a med destroyed my ability to sleep and function and relax, and now I'm so injured my level of exercise is not only gone in one year from intensive to very little but my pain is still really high. I'm noticing it in how I sleep, in how I feel, in everything, because my body is so used to a lot of exercise and now suddenly it isn't getting it. That's why, given you've reported that you're been a regular exerciser for a long time, that puts you in a different category than someone who is active but doesn't formally exercise all that much but eats the foods and takes the supplements that protect the heart from oxidative damage. So to me, again, I'd make sure your life includes what you need because of how you've lived so far -- you can't go back and get a do-over. Here's hoping you can work with your family to make that happen. But to others reading this who haven't yet established long-term habits, it turns out that movement and lifestyle are more important than formal exercise, at least according to the studies of actual humans as opposed to theoretical studies. Those folks on the so-called Mediterranean Diet, who don't only live in the Mediterranean, are not known for a lot of formal exercise. They aren't known for avoiding white flour. They are known for not being sedentary and for eating well.
I’m not a medical doctor and nothing is going to completely ensure your heart health, but here is what I could find:
Current US guidelines suggest adults get 150-300 minutes of moderate intensity aerobic exercise (which includes walking) or 75-150 minutes of more vigorous aerobic activity per week, preferably broken up across the week (like 30 minutes, 5 times a week).
The guidelines also suggest doing muscle strengthening activities that involve the whole body twice a week (like weight lifting or body weight exercises).
Only about 23% of Americans (19% for women) are actually meeting the minimum guidelines though, so you are not alone. If you cannot get up to the “150 minutes” which may seem daunting to most people, even a little bit of exercise is better than no exercise at all and has some health benefits. If you are stuck at home and can break it up throughout the day, that can be as beneficial as doing it all in one go, and keeps you more active throughout the day. If you can go for short walks outside, that might be a good way to start, even if you are only doing 5-10 minutes to start out.
Some people find that if they use a step counter (like a FitBit or smart watch), that encourages them to reach a daily goal of a certain number of steps, and can help you make sure you are moving enough throughout the day. (These can sometimes be expensive, but there are some very basic ones out there that just record steps, or even steps and your heart rate, that are affordable for most people.)
If you are trying to lose weight, I have found that diet is much more important than exercise in overall weight loss (for myself), but adding a little light weight lifting to add lean muscle definitely helped to rev up my metabolism.
Good luck, and remember, even if you are just doing a little, that is better than no exercise at all.