Hi Caathy, welcome. I'm a relative newbie too, I've been primal for about 3 months and have had very good results. I went cold turkey off of grains and sugar and it was much easier that I thought it would be. (I still have a little dairy, mostly cream in my coffee and occasional whole milk yogurt.) My secret weapon is lots of good quality fat - coconut oil, avocados, eggs. I do count calories and carb grams.
Especially given the health challenges you've had, I would encourage you to not focus on weight loss but on getting the best quality nutrition you can so your body can carry on with the healing process. I am 55 and I can tell you that there's no time like the present to start making the rest of your life better.
You are welcome to check out my journal if you want more info on what's worked for me so far. Good luck to you!