Wait it out - it will pass! That is the good news :O) !!!
In the meantime, you could try drinking some strong peppermint tea. Also, if you have access to essential oil of peppermint you could apply a few drops on your skin at the base of your skull and a drop on each temple. Be very careful not to get it in your eyes - it doesn't feel pleasent! This will feel very refreshing and also take the edge off the headache.
Also, when possible get lots of rest and don't over exert yourself. (just for your own comfort)