Experiencing painful cracked corners of mouth, a condition which is also known as angular stomatitis, might be intolerable. This kind of condition might be brought about by a number of reasons such as vitamin deficiency, yeast infection, or drooling. The main symptoms involve the appearances of redness, swelling, and sores at the corners of the mouth. Ways to get it healed include keeping the area dry, applying the lip balm, and eating a balanced diet that has fruits and vegetables high in vitamins. 

Taking care­ of oily, acne-prone skin is a priority for many tee­nage girls. Sunscreen plays a vital role­ in skin protection. Choose oil-free­ and non-comedogenic sunscree­ns. These won't clog pores or make­ your skin greasy. Look for zinc oxide or titanium dioxide ingre­dients. They are ge­ntle. Sunscreen pre­vents skin damage and premature­ aging. Establish a daily sunscreen habit for healthy skin.

Excessive sweating, also known as hyperhidrosis, on the other hand, can arise from a large number of causes like anxiety, hormonal fluctuations even certain medications. Your thyroid and blood pressure readings are normal so we should move on to other causes like stress or diet. Keep your body cool, use breathable fabrics, and don't forget about relaxation techniques like deep breathing or yoga, and you will reduce sweating. If it gets worse, you should talk to the doctor about it first.

It's a common issue when sweat and oils get trapped in our skin pores. Prolonged sitting can make it even worse. The best over-the-counter treatment is to use a mild cleanser with salicylic acid to shrink the pores. To that end, also, take breaks from sitting and keep the area clean and dry. Stay hydrated and wear loose, breathable clothing. 

Not taking proper food for so long can damage your body severely. The symptoms you talked about, for instance, your constant feeling cold and desire for hot water all the time, could indicate you are suffering from something serious such as malnutrition or damaged organs. You are supposed to go to specialists for diagnosed tests and treatments. You have to understand that it's not too late to get good treatment and work towards being healthy.

I advise you to follow a proper skincare routine which includes washing your face twice a day with gentle cleanser and using a moisturizer that suits your skin type. Also, while going out wear a sunscreen with at least SPF of 30. Also, exfoliating 1-2 times a week can help. And avoid touching or squeezing your pimples as this can make your problem worse. For more help and guidance regarding your dark spots, I recommend visiting a dermatologist. I hope this proved helpful.