Hi, Welcome to Health care magic forum.
As you describe, you are taking about 20 nuts of cashew and pea nuts daily, have more fats, which alone may not be causing the bulk, but the other calories,and fats, combined might have caused the weight gain.
I advise you to take the almond nuts, which have the healthy fats, and may be suitable for you.
To reduce the belly fat, and weight you can follow the 3 steps.
Reduce the calories, and fats in the diet.
Increase the activity by practicing the
yoga,morning walk, and do any work in front of you what ever the work is.
Reduce the sleeping time, practice late to bed and early to rise, and avoid the day time sleep.
Wishing for a quick and complete recovery. Thank you.