Engine damage after 65,000 km

Hello MOTOR-TALKer, I’m new here so I ask for insight into possible errors. My car: Seat Ibiza 6J , 1.2 70 HP, Built: 2009 with almost 65 000 km on the clock. Now to my problem: after a disco visit I wanted to bring myself and my buddies home safely. When I then feel a small need at 3:00 am at night I stop at the roadside, turn off my engine and finish my business. Not a minute later I get back in the car, want to make the engine and then that: engine starts immediately but with a very funny noise. (Had sounded for me after ONE cylinder failure). I turned off the engine again and challenged my luck for the second time. engine starts on but with a more disgusting noise. (Heard after a ZWEI cylinder failure belongs). engine and car towed to the Seat dealer. This then meant after a “control” (for 180€) that it must be something bigger. In the worst case cylinder head damage. I noticed immediately that I neglected the service after 2 years and my oil was already 30,000 km old. He now meant that he will look into the engine with an endoscope after the weekend. His prognosis then after the weekend was that the steering chain has skipped (because of lack and old oil). My car had too little oil before me Spanish because we looked at the oil at half past 4 and there it was exactly between MIN and MAX. I can’t really judge the old oil. I only know that my parents with their Opel with 192,000 km have not done any service for a long time and it runs. In any case it cost now 640€ WHEN the valves are still good. Today (one week later) I find out that the car is still not running and now also the valves have to be changed. Estimate 2.190 €. Now as a student I stand there like a complete idiot. I have worked out a nice car and now I should 1/3 of the value for a motor repair?? Can one now answer me whether this can be all, that e.g. the control chain can skip because of “old” oil. And what would you do now? I hope someone can give me productive advice and please no moral apostles with: Would, if, If. I really can’t use that anymore. The situation is now and I can’t change it even if I didn’t want to – thank you in advance.