I had that EXACT same problem a couple weeks ago.

You most likely have an oil sludge issue. Your oil pump is probably clogged with oil sludge. And your head is being starved of oil, that is what is causing the ticking noise (your lifters aren't getting enough oil).

If you drive with your car that way, you are most likely going to screw up your motor/turbo. I just had to replace my turbo because of this problem, I was lucky I didn't damage my motor.

You're engine definately needs a de-sludge treatment. I would recommend auto-rx. See www.auto-rx.com . Read about the de-sludge treament on their. Hopefully your oil pump doesn't need to be replaced.