The diarrhea may be related to the other symptoms you have because of congestion. On the other hand it may be a separate issue. Have you eaten anything different? Diarrhea is the body's way to get rid of toxins, poisons and irritants.
Have you been in contact with anyone who has also been ill, or have you been abroad? You do not need to answer this, it is just something to think about.
Don't bother with eating and do not drink any milk or eat any dairy produce until you are clear of the diarrhea for a few days. Drink plenty of diluted squashes or any energy drinks, but take small swigs often. Clear soups will be fine too (no cream in the soup).
If you have someone that is able to go to the pharmacy for you, ask them to buy the solution to replace your electrolytes (the pharmacist will be able to tell you what these are). As you live in a different country to the UK, the solution may be called something different.
Telephone your doctor's practise and explain how you feel and that you have the constant diarrhea and the stress the fact that you also have chest pains and your other symptoms. Ask for a home visit.
If your diarrhea is settled, then make an urgent appointment to see your doctor. If there are no appointments available, do let the staff know of your chest problems or consider going to the ER.
You may have a respiratory infection, but the symptoms may also be related to a heart condition.
Let me know how you get on.
Wishing you a speedy recovery.
Maybe the stomach flu. I'd go to the doc and get checked out. Make sure you have plenty of fluids diarrhea can cause dehydration