Up n down on the scale

I hope this is my last diet attempt. I've been fighting this battle my whole life, losing then gaining. I'm 60 years old grandmother that wants to be healthy. I started the keto diet 4 1/2 weeks ago and lost 20 lbs. I like this diet, it's one that I think I can stay on & it doesn't get old. Been on medifast, nutrisystem, low fat, low cal and one time, anorexic (not really proud of that one). I'm an accountant and a gun store/gun show owner.