Hi Cathy, welcome! I'm almost 48 (2 days to go!) and also have really bad family history of heart disease. Started eating vegan, mostly whole-foods based diet a little over a year ago. You will find that it is really worth the effort. And don't be discouraged if you slip up sometimes, or even a lot (I'm a living testament to slipping up...
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Here's a suggestion someone made to me when I first started, and I'm really glad I did it. It's helped me get back on the wagon on many a day:
Make a list of all the big & small things that tell you you are not as healthy as you want to be. Not just the number on the scale: The aches & pains. The cholesterol level. Your fasting blood sugar level. The out-of-breath up the stairs. Places you'd like to sit where the seats are too small. The number of sodas you drink a day. The medications you take. List anything and everything you can think of. Then put it in a place you won't lose it (or post it in here in your journal!).
After a few months, check back. You may be amazed at how many "little things" have improved!