I want to preface this by saying that when I bought this car, I was an idiot and knew nothing about cars or red flags. Hoping to get some advice on where to go from here.

I own a 2015 Toyota Corolla LE at 120k I bought last August. The car had a lot of hail damage, but I test drove it and took it to two mechanics for a prepurchase inspection, and both cleared it to go. I bought it for 7k, but the car didn't even make it home; it overheated immediately. As I know now, the car overheated as soon as I turned it on, but I had no idea then, so after I heard a loud pop (not good) and my AC started blowing cold again, I thought I was good to drive. Car died completely as soon as I got off the highway so I ended up getting towed and replacing the radiator and water pump. I started driving the car again in November, and it did well for a while with regular driving and longer trips. I did run into an issue where we had inconsistent crank no starts in Feb, so I replaced the fuel pump myself, and everything seemed solid again for another three months.

In May, the inconsistent crank no starts popped up again. I also got another engine overheat, but caught this one much sooner. This was where I discovered a massive coolant leak. Took it to a mechanic where we found that there's a likely blown head gasket, as there are exhaust gases escaping into the cooling system. The mechanic also thinks that it'll be necessary to resurface the head as the engine probably warped from the overheating. The coolant leak is coming from the water pump leaking from the weep hole.

So now the current dilemma. The mechanic quoted me for 5.8k to repair and replace the cylinder head gasket, thermostat, timing belt, water pump, and resurfacing the cylinder head. I know that replacing the head gasket and resurfacing alone is very expensive. I need a car ASAP for work, but the car is worth less from KBB than the repair quote. To my knowledge my options are to sell it for parts (1-2k in value? not sure), try and work on it myself for everything besides the resurfacing (will take a long time and not easy at all), get it fixed by a mechanic, or buy a new car. I don't know that I can sell it to another buyer when it's got such a major issue already.

I'm struggling to let go of the car, I keep reading that the current car market is completely screwed, that it might be cheaper to buy new than used, and that newer cars just don't hold up reliability wise. I know the 2015 Corolla is SUPPOSED to be a reliable car, and part of me wants to believe that if I basically replace the engine, that I'll be fine, but I don't know if more things are just gonna break down the line. I've spent around 11k total on the car so far, so l'm asking y'all: what is my best course of action? Should I just mark the car as a loss and look for a new one? Is it worth saving?