Weight loss aside, what has happened over the past 30 months has been an amazing and highly educational experience for me on so many levels. There were so many ailments and limitations creeping into my life that I chalked up as being a result of my age and/or obesity that were actually a result of high blood sugar from a poor diet and lack of physical activity. This WOE combined with increased physical activity is the fountain of youth. I have rolled back the years. This healing and rejuvenation process was underway from the beginning. Diet helped a lot, but I think getting moving again with daily walking did too. My chronic aching back got worse before it got better, but it did get better. Age takes its toll. I am not 20 again. But I feel better in my 50's than I did in my 40's. Don't let age stop you. Ease into what ever you want to do and then go from there. With time and dedication you will be amazed at what you can do. I remember seeing one of those 'feel good' stories on the news several years ago where an 85 year old woman completed a marathon. The amazing part was that she didn't even start working out until her 80's. Our body can do more than we think if we treat it right.

I've been using THIS Calorie Calculator to kind of judge where I'm at with my eating. It has proved to be reasonably accurate IMO. I plugged in your data and it showed that you would be maintaining your goal weight at about 1900 calories at the light activity level. If you decide to increase your exercise, you may want to consider eating a little more. When I was eating between 1800 and 2000 calories a day I did that because I'd broken my foot and that ended my walking routine for a month or two. I wanted to keep losing so I really tightened up on the diet. Once I started to heal I started walking again and I'd even started a little weight lifting. But I didn't change how much I was eating. I wasn't eating enough for the level of activity I was doing and I felt drained. I needed 2 or 3 rest days between weight lifting sessions to get my strength back. The diet that I had enjoyed before I broke my foot was not so enjoyable anymore. So I added about 500 calories to my diet. I felt so much better after doing that. I got the pep in my step again on my walks. I recovered faster with the weight lifting. I was happier and I was still losing weight.

I don't normally like to tell others what to do. We are all so different. I like to just say what I did and let others draw ideas from my experience. In your case I would suggest experimenting with getting a few more calories in. Experiment with different levels of protein. Keep the carbs low. Find the right zone for you. Other than some achiness from initiating a new exercise, there is no reason that you should feel drained from your swimming and other workouts. You need to have enough gas in the tank to be happy. You are eating right and doing what is right for your body. You have plenty of time to tweak your diet and figure out the best diet for you.