When you have a sinus headache that won't go away you can lay in a reclining position and play a hot towel over your eyes and nose.
Just don't make it too hot to burn yourself but hot enough so that it warms your nasal passages which can help clear up a sinus headache.
You can also take a steamy shower and allow the steam to warm and moisturize your nasal passages which helps to relive sinus pressure and helps get rid of the sinus headache.
If you have a sinus infection then you should see a doctor for treatment because some sinus infections can get bad enough to kill a person.
But if you're just experiencing a sinus headache then it will usually eventually go away.
But try irrigating your nasal passages as well and constantly use a hot towel to help keep your nasal passages warm and use a humidifier in your home or bedroom at night.