Forgot to add that I'm also sometimes feeling pressure on my face, where the sinuses are and my nose blocks at random times for absolutely no reason. I don't have a cold or anything like that, nor did I have one for a few months. It's been like this for at least a month now.
Hi and welcome to the Migraines & Headaches Community.
You are describing typical tension headache symptoms. I think that once you get through your exams you will start feeling better. In the meantime, make sure you get plenty of sleep--try ZzzQuil, it is non-habit forming, Excedrin is a real good OTC medication...and yes, drink, drink, drink.
If you are not feeling better after your exams then come back and I can help give further tips. Good luck!
Should I contact a doctor if the headaches don't stop? Can tension headaches lead to something serious or are they a sign of something?
IF it is truly TENSION headaches they are not harmful and the only thing that will help is to try to reduce your stress, which is why I said to see how you feel after your exams.
If it is not tension then that gets into a whole different ball game...but, I would not make that leap right now. And remember, stress over the headaches is still stress and you need to alleviate stress so, try to stop worrying about them at this point.