Hi and welcome.
I think we all have that gobsmacked feeling when we get the D diagnosis. My reading was 22 when I was diagnosed but I had already spent 2 weeks prior to that cutting out all the sugar/sweet stuff because I pretty well knew from my symptoms what the problem was.
There is a lot of guilt associated with Diabetes but you should not accept that. I was the same and felt really bad that I was going to become a drain on the NHS and it was all my own fault. I found a very interesting and emotional TED talk video by a well respected American Physician called Dr Peter Attia really helpful in understanding and coming to terms with it ...
As regards, your diet, as others have said, using your meter to test before a meal and 2 hours after will give you an idea of which foods cause you the most problems. Generally speaking it is the carbohydrates in grains and grain products, (bread, cereals, rice, pasta, noodles, porridge etc) vegetables that grow underground (potatoes, carrots, parsnips, beetroot, sweet potato etc) and veg that grow above ground like peas, beans, lentils etc as well as fruit and of course the obvious sugar products. Some of the above will affect you significantly less than others which is where the meter comes in. so all of the above are not necessarily off the menu but many need to be significantly reduced.
It may seem like that doesn't leave much that you can eat, but it is surprising how varied and enjoyable your diet can be once you get your head around it. You will have spent your whole life packing your plate with carbs at every meal.... we all have..... I still feel guilty about eating a curry without rice or a naan even though I enjoy it and my BG stays reasonably within range because it seems wrong and somehow decadent! It takes a good few months to get out of that habit and find a new way of eating and learning what to put on the shopping list.
Things that most diabetics find do not cause them problems are eggs, meat, fish and mushrooms. Dairy, particularly whole milk products... low fat options are always higher in carbs, so not ideal for diabetics. Leafy greens ie cabbage kale spinach etc and broccoli, cauliflower, aubergines, courgettes, peppers, tomatoes. Nuts and seeds and olives are great snacks. Fruit needs to be limited and most people find berries best although not grapes. The more exotic fruits like bananas, mango, pineapple, etc are best avoided or eaten in very small quantities, so maybe split a small banana over 2 days. Raspberries are currently in season and delicious and one of the lowest carb fruits and make a really nice desert with creamy Greek yoghurt or cream. There are low carb bread options in the supermarkets these days although I almost never eat bread anymore. That said, I bought a loaf today which is the first in months. It was reduced and I thought it can go in the freezer for some occasion when I may need it.
I often start my day with a mushroom onion and cheese omelette with side salad and avocado and that keeps my Blood Glucose steady and sets me up for the day, so I only need a few nuts or a chunk of cheese at lunch time and then meat or fish and veg on an evening with a small portion of potatoes and some rasps and yoghurt.
Once you cut your carb intake right down, it should naturally follow that you lose weight, but increasing your exercise level will also help, even if it is just a brisk 15 min walk each day.
Good luck and keep us posted with your progress. Here on the forum we love to celebrate each other's achievements but we are also here to support each other through the times when we struggle or lose our way. Feel free to ask whatever questions crop up. It is a big learning curve and we are all going through it together here, just at different levels.
