Hey Jake, welcome!
You are in a good place for support and advice. I started out much heavier (almost 23 stone) and older than you. Today I am approaching your 15 stone, and still trying to lose a bit more. If I can do this you can too.
My first piece of advice is to suggest you start a diary on the Weight Loss Diary page (
https://weight-loss.fitness.com/forums/weight-loss-diary.9/ ) and tell us more about yourself and your goals. Its the best place to get advice and support from others.
You will hear from people on the forum that whilst exercise is important for your health and an aid to weight loss, most weight loss comes through reduction in calories. No real way around that. Before I started this diet I would have said much of the same thing about vegetables, but now I eat a lot of them and like it.
My transformation came when I buckled down and decided that I was not going to let myself live on high calorie junk food any longer. I started what I thought of then as a "kickstart" diet, it was going to be just 3 weeks long of just 1,200 calories a day, no exceptions. I figured I could do that for 3 weeks. I quickly learned that without eating a lot of fruit and vegetables I could not keep from feeling hungry most of the time on a 1,200 calorie diet, so reluctantly I started eating some. After a time I started to like the veggies, and I learned which ones I liked better and how to better prepare them. Now I look back on that time as my withdrawal phase, it wasn't easy, but things got easier with time. Well the "kickstart" is now in month 10 and I am down about 7 1/2 stone. It has gotten much easier. If I can do this, you can too. I am no smarter than you, just older and uglier.
You are clearly wiser than I. I wish I had started this at age 21!
Best of luck to you, and I look forward to following your progress.