Welcome and yes, your head will be going crazy - mine did for 2-3 months. But well done on taking steps to address your condition.
Lots of good advice above. Mine is: exercise helps. I walk. I enjoy it, it's free (apart from suitable footwear) and there are plenty of places round where I live to do it either out my front door or within a short drive. It also doesn't damage my knees. I got a very cheap tracker (Mi Band), started (I think) with 5,000 steps a day which is now 7,000. If I go for a walk I'm usually well over that, and as far as I can tell the evidence is that over 7,000 - 8,000 steps per day one is into diminishing returns. I try to walk on unmade surfaces - it's more interesting and better for my knees, indeed for all of me. And it's a great time of year to start, as Spring is definitely springing.
I altered my diet in that I've mostly cut out carbs with my evening meal. I still have porridge for breakfast (no sugar, honey or syrup) and a couple of slices of home-made sourdough at lunch, which I can cut very thing. I've discovered cauliflower rice, and Edamame & Mung Bean Fettuccine, and I find a spicy dish with pulses is fine without either. As well as looking at carbohydrates, I also did a lot of Googling for GI. I suspect there are more decent substitutes I've not come across yet. I'd like to try spaghetti squash but I'm not sure they are ever sold in the UK, or at least in my somewhat rural part of it.
I also accidentally gave up drinking about 3 years ago - I make an exception when I am out for a meal or have people round for a meal, I've not taken sugar in my tea since I left home, I don't like soft drinks, with the exception of tonic water with gin and I am mostly quite happy without cakes etc..
My fortune is that I like cooking, I've cooked most of my meals most of my life since leaving home, and I can afford whatever ingredients I want. Also, I live on my own and whilst the cats sometimes want to help me with my food, I don't have to accommodate a partner and/or children.