The average dieter undercounts their calories by 400. Even trained nutritionists undercount by over 200, so it is very very common. A lot of it is just forgetting things or mis measuring, but some of it is because nutrition labels can be off by 20%.
2 eggs: 160
2 slices whole wheat bread: 180
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360
1 cup porridge: 300
1 scoop protein powder: 100
1 tbsp chia seeds: 70
1 banana: 100
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570
Cod fillet: 190
roasted veggies: 50
250g potato: 260 calories
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510
I come up with 1430, but I'm guessing some of your quantities. Still, that is without any added oils, butters, or condiments or any juices, sweetened/creamed coffees, alcohol, candy, etc - and that is where hidden calories often add up fast.
As for energy expenditure, I'm estimating you are burning 1550 a day without exercise - roungly 1 calorie per minute. You're doing 290 minutes a week of pretty intense exercise that I'm estimating has an average MET of 9. That means you're burning an extra 8 calories for each of those 290 minutes - about 2500 calories a week. Combined with the 840 calories per week (130 calories per day) from your diet, you should be burning an extra 3340 calories a week or 0.95 lb of fat per week.
So if you ate like this every day and exercised consistently, I would estimate that you'd lose about 6 lb of fat and potentially gain some muscle to offset that weight loss. So I'd expect the scale to maybe 1-4 lb lower after 6 weeks, which is within the daily fluctuations of water retention, colon load, muscle swelling, etc.