I Have Had This Pressure On My Forehead For Nearly

I have had this pressure on my forehead for nearly a year. I've always felt this mucus like substance in the back of my throat that I constantly swallow it for as long as I can remember. I've been to the doctor and was told I had a sinus infection. I was given pills to help and I believe it did relieve the pressure, but it did not fully take away the pressure. I also believe it could of helped cure it if I didn't struggle with taking pills meaning that I didn't take all of them. With this pressure or pain on my forehead, I have had a headache for a minute from time to time, but today it lasted quite a while (30 - 40 minutes). I've been scanned in case and I don't have any tumor in my head. I still don't know if it's my sinus infection or something worse.