Type 2 diabetes would give you recognisable symptoms For example when your blood sugar is high, you may pee more than usual, especially at night. And you may feel more tired, because your body can't get enough glucose in to your cells for energy. Other symptoms include losing weight without trying, genital itching or thrush, cuts and wounds taking longer to heal, blurred vision, feeling extremely thirsty.
It’s not so much about the sugar you consume, but about an unhealthy lifestyle - unhealthy foods, being overweight, lack of exercise or being sedentary, among other things - which results in your body losing the ability to regulate your blood sugar. You can also be genetically pre-disposed which increases your risk. Don’t know if you go for regular health checks with your GP but if you do, there would be a routine blood test - HBA1C - which would identify if you are pre diabetic, so you would have been alerted, given advice and monitored if this was the case. If you’re worried you may be diabetic, or pre diabetic then it’s probably a good idea to see your GP who can arrange for the test.
Diabetic foot is caused by consistently high blood sugar which can cause diabetic neuropathy - a reduction of sensation in extremities like hands and feet. High blood sugar over time damages the blood vessels and this can thin the skin on lower legs and feet, meaning that minor injuries can be difficult or impossible to heal and cause ulceration. Your photo doesn’t look like diabetic foot - and you say it’s painful, which diabetic foot generally isn’t, but it should definitely be checked out by your GP.
And artificial sweeteners are implicated in the onset of type 2 diabetes, so maybe that much Diet Coke isn’t a good idea even if you are not diabetic. My partner has had type 2 diabetes for about ten years and was advised to use artificial sweeteners in moderation. You can google which ones are safest, but moderation is the key. Also a no no for diabetics is salt substitute. Diabetes can affect internal organs like kidneys, but this entails learning to cut down or do without, as commercial replacements can cause complications.