Hi. Firstly you should know that there are many reasons which might cause the symptoms you have but based on the history you are giving I am thinking it might be gastritis. So I suggest you to follow a healthy diet consume berries, nuts, green leafy vegetables rich in fibre, avoid coffee and tea, avoid spicy and oily foods, avoid junk foods, prefer ragi malt, buttermilk, lassi and most importantly never skip meal. Untimely food habits can also cause this so follow a routine. Have plenty of fluids atleast 12 glasses of water daily. Do yoga and meditation. And as far as your pimples are concerned it might be because of excess female hormones,infection or allergies etc so kindly consult a dermatologist for further management.