What is leaking out of my ear?

Hi.

Over the weekend I got a cold, runny nose sneezing headache etc. Around the same time there seemed to be some kind of leakage coming from my ear. It feels like water but it hardens up, somewhat crystalizes and is yellow and sticky. I put a cotton bud in to try and remove it but it keeps coming back so that isn't working.

When I wake up in the morning I can look at my pillow and there are yellow stains on the pillowcase from where the ear has leaked overnight. My ear doesn't hurt and I can still hear pretty clearly.

Thanks