Diabetic with lack of discipline & motivation

Welcome. Coming here is a first important step. You just need to keep taking those steps forward. You can definitely do this, but what it really takes is patience day-to-day. Get your daily calorie goal from MFP. Get a digital food scale. Start weighing and measuring all food and drink. Log it all in your food diary. At the end of the day you should be within your goal. That's it. Everyday.

As you go on, you'll find yourself making food choices to fit your goal. You will most likely change your way of eating a bit. Try to build new habits, because when you lose the weight, you don't want it back. You are retraining yourself to eat correct portions for you. You can and should eat food you enjoy--just not too much.

Also, if you are not exercising, try to start some type of movement. Walking is fine. Log your movement into MFP and you will get more calories for the day.

I wish you great success.

It sounds like you're taking some very positive steps (figuratively and literally!). Small changes add up over time, and manageable changes tend to stick longer term. You can do this.

One thing that was important for me, getting started, was believing that it was possible to improve fitness, lose weight.

When I joined MFP, I was already 59, menopausal, and hypothyroid (though properly medicated for that). "Everyone knows" that women can't lose weight pasts 50, past menopause, at any age when hypo, etc., blah blah blah. Sometimes "everyone knows" things that just aren't true, but those myths tend to sneak around in some subtle spots in our self-expectations. (I'm not obese any more, BTW - haven't been, for well over 6 years now, after around 30 previous years of overweight/obesity.)

To help with self-expectations, exorcising those myths, one thing that helped me was to look at threads in the "Success Stories" part of the MFP Community. There, amongst many reports, you'll find stories by men around your age who lost weight, got fitter; diabetics who improved their A1C, were able to reduce (sometimes even eliminate) meds; etc.

Here's just one example of improvement in someone diabetic, with comments from others:
https://community.myfitnesspal.com/en/discussion/comment/40753201#Comment_40753201

Another motivating thing for me was finding that along the route - long before goal weight was achieved - there are dozens of smaller, positive life improvements that happen via being more active, getting better nutrition, or just beginning to lose weight. There's a huge thread with a bunch of those here, to give you an idea of some good things you can anticipate as you move forward:

https://community.myfitnesspal.com/en/discussion/1275030/whats-your-most-recent-nsv/p1

Wishing you huge success - the effort is worth it!