Re: Hod do I know if I have hig BP? And what do i do about it?
I agree with red-rider, that this is more likely a sinus problem.
High blood pressure is usually symptomless, that's why they call it "the silent killer".
Since over-the-counter stuff isn't helping much and you haven't had a check up in quite a while (no GP), PLUS you're 34 and a bit overweight, this is probably a good time to get a full check up with a doctor anyway.
As red-rider said, buying a home BP monitor is a good way to track your own blood pressure, but if you go to the doctor and your BP is normal you don't need to invest in one!
It sounds as if you are in the UK, yes? And have national health insurance?
So ask some friends for a good GP and get a baseline once-over, plus he/she will most certainly help you with the congestion and headaches.