I've spent years trying all sorts of diets and exercise plans.
I did lose several stones a few years ago through a plant-based (with very little processed food or junk) diet. I also did c25k and then joined a running club so I'd do club once a week plus a couple of 5k runs. I lost about 3st in just under a year.
As is often the case, I put it all back on then gained another stone this year during lockdown.
When the gyms opened again, I started going every day at 6.30 and did c25k from the beginning on the treadmill (I've realised I don't hate running-I just hate running outside!)
I did that for about 1 month but with no changes to my diet, I only lost a couple of pounds.
Then I started meal planning and kept calories low. I focussed on macro splits and low-cal high-density foods with protein. It's boring as hell but in 6 weeks I've lost 17lbs.
I'm still going to the gym and doing a slow run every day. I average around 5-6k in 40 minutes and am increasing my time to an hour on the treadmill whilst lowering my calories a little.
It's a huge calorie deficit but I have a feed day once a week with more carbs and calories which helps to reset metabolism apparently.
It's not a long term plan- I'm going to change it up in a couple of weeks and increase my calories a little with different foods- but it's been a brilliant kickstart.
I feel so much fitter and, like you say, the exercise helped me get into the right mindset then it was much easier to get the food right.
Seeing it as an 8 week plan has also really helped as I know I can change it up once I've achieved this goal. Then I'll reassess and replan.
I don't know if that's any help to you but it's certainly worked for me!