I just lost an essay for you on why you should relax about this. not writing again so points below.
Perspective - get some, this is not a big picture catastrophy, repeat after me 'in the big picture of my life this is insignificant.'
Everyone looses money at some stage, its not such a big deal. Ive lost at least 10 times that much over the years on mad hobbies and schemes.
Your worst case is you blow a few thousand on a good repair or you sell at a loss of a few thousand. This is not worth the anxiety you generating for yourself.
Now chin up and chest out and next moment you have spare, go out lift your bonnet and start learning all the bits.
Pick the bees outa ur radiator n intercooler.
Pick the leaves out of ur leaf catching thingy under ur windscreen.
Get underneath clean up the oil leaks and work out roughly how much is dripping and find out exactly where from.
Tighten any loose clamps even, degrease/clean each component, check uve got spare fuses in the spare fuse spot, etc blah blah.
Educate yourself on what you can see.
You will do yourself a BIG favour by going to any of the aforementioned specialists armed with a basic understanding of your cars mechanical properties in place of your current gloomy outlook. Take it in clean without the sob story also.
Chin up - you bought it, your going to get it fixed and youll love it or your going to sell it and learn a lesson unlikely to be repeated.
Stop berating yourself man it will achieve nothing positive.
Anyway the tasks/tinkering listed are pleasant to do and will make you feel less anxious for sure.

Tl;dr you bought a car and it may need some repairs = not such a big deal. Perspective bro.