It seems like a case of fungal infection; a skin condition that may cause itching and redness on the lower part of the skin. It is caused by germs which thrive well in warm and moist areas. Keeping the skin dry and clean, using antifungal creams as well as putting on loose clothes can be helpful. To avoid further irritation, kindly refrain from scratching.

It looks as though you burgeon an umbilical granuloma which is a small piece of tissue that protrudes from your belly button. The yellow discharge may be an indication of the infection. In some instances, it could come on without any pain or swelling. To do this, you have to keep the area clean and dry. It is also possible that you will need antibiotics when the infection gets worse. 

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.

Syphilis is an infection passed through sexual contact. It can cause sores, a rash, fever, and damage to the body if not treated properly. Doxycycline and ambroxol capsules won't heal syphilis. Syphilis is treated with certain antibiotics that are prescribed by doctors. It's the right way to get a diagnosis and treatment of complications. Don't let it go on; go to a doctor if you suspect you have syphilis.