Welcome!
Another OLD person here. 53.
What I have learned, is to track your food, track your exercise, journal your thoughts and moods. Write it on paper, log it online, rant here, blog it or whatever is your style. But the big thing is, this is a lifestyle change, NOT a diet and there is NO failure, only FEEDBACK!
Log it all, sit down once a day or once a week or once a month or whatever suits you, go over all your logs, and learn from it. Don't beat yourself over the head, just look at it objectively, tweak and carry on!
Personally, I go over all my stuff on the last day of the month. When I was losing, if I was down, even if it was only a pound, SCORE! Now that I'm maintaining, as long as I'm within my 2 +/- range I'm good!
Another thing, because this is a lifestyle, it's ok to do it slow. If you have to start with just overhauling your breakfast and exercising 5 minutes a day. Go! Get that down, when you have that down, tackle another step.
I've lost and gained over the years, but my biggest success has come from tracking and slowing down and deciding to work on making the good habits stick, no matter how long it took. This last round it took me 10 months to lose 30 pounds, but I've kept it off for over a year, and I'm still hitting the gym and loving it!
I'll get off the soapbox now!

Carry on!