You have loads of time! I’d suggest starting by keeping a food diary. Don’t start trying to modify your intake straight away; just record it for two weeks. Literally every single thing you put into your mouth should go into it along with what time you ate it. You’re not going to show it to anyone, so there’s no reason to minimize.
Once you have two weeks of info, look over it. Some patterns should emerge. For example, you’re eating a lot more sweets than you thought. Or you’re eating way less fruit and vegetables than you thought. Wow, you’re not eating much lean protein, are you? And you’re eating a lot of bread, or drinking, wow, two or three Starbucks a day? The first time I did this, I was genuinely amazed by what I saw. My lizard brain was “helping” me forget all the crap I was eating.
Once you have the data, you can start changing things one at a time. Personally, I eliminated 90% of the refined carbs, including sugar, in my diet (for me, carbs get converted to belly fat in what seems like a matter of minutes). I started eating a lot more protein (eggs, chicken, fish) and veg (whole avocadoes are great for your skin). I started eating several small meals and not letting myself get so hungry that I would raid the snack machine (eating small meals more frequently also help rev up your metabolism). I started drinking at least two liters of water a day. I never counted calories, but I did keep up the food diary for several months until my new habits were ingrained.
Also, if you don’t already, start exercising every day. It doesn’t have to be much – a quick run, or even a long brisk walk. Exercise does very little for weight loss compared to diet changes. But it is a huge mood elevator and helps you feel better about yourself. Strength training is good for raising your resting metabolic rate. If you have the time and money, yoga is also excellent for lifting depression and helping you be more mindful, which can help if you have a tendency to overeat mindlessly.
The only other thing I would say is, don’t judge your progress by the scale. I weigh myself very infrequently, and only out of curiosity – I think how my clothes fit (or don’t fit) and how I feel phycically is a much better measure of progress. I weigh more now than I did 15 years ago, but the clothes I wore then are too big for me, because I’ve redistributed my weight and put on muscle while subtracting fat.