Once I hit peri, everything changed! Nothing that worked before worked then. My diet was the same, I was exercising more - and just getting fatter.
I hated the new gut I had (that was definitely new!) so I tried a few different things and this is what worked:
I spent 2 weeks logging everything I ate into My Fitness Pal. Every single thing that went in my mouth was logged. This was both boring and enlightening because, like you, I had a good diet but I was eating and drinking way more than I actually thought.
I joined Macros Inc on FB. This is free and you put in your current weight, height and target weight and they calculate your daily calories and macros (protein, carbs and fat). They give you a realistic target (I got a lot more with them than on weight watchers) and focus on good quality protein.
I then continued to log everything, making sure I stuck to my Macros.
I ditched a lot of my cardio (I am old school, I like running and aerobics) and replaced with strength training. I bought some cheapo weights and started doing Sydney Cummings workouts, they are free on Youtube.
I made sure I got 10k steps per day
For the first 2 weeks, I stuck to it religiously and nothing happened. I was getting the arse with it, but then in week 3 I lost 4 lbs and it continued at a steady 1 - 2lbs per week after that. I am now back to the same size and measurements I was in my 20s, my wedding dress fits!
I still train at least 5 times a week ( I use much heavier weights now) and get my steps in and I follow my macros Mon-Fri but I take weekends off. This means I maintain my weight. Its a bit of a faff to get started but it does work. Good luck x