hey man i work on my car all the time build a project car from the frame up. It sounds to me like you've lost your head gasket. The gasket between the cylinders and the coolent.

Cheak your radiator Take the cap off and look inside. if you see oil floating on the top its deffinently the gasket.

You didn't mention anything about smoke though the only thing is you should have been seeing grey/whitish smoke if coolant and oil is being combusted.

the ticking is deffinently your valves i wouldn't worry about that now its just a consequence of your engine not firing properly because theres oil and other shit in the cylinders.

If it is your head gasket and your a student i'd look it up serious about how to do it yourself. It looks like a very hard job to do since u have to take apart the engine but its really just the value cover its not that bad deffinently do able if you read and take your time. Don't waste like a grand for a dealership to do it.