sounds to me like you need to learn somethin' about cars! The problems you're describing are mostly wear items. Tires and struts wear out. It's just a fact of life. The check engine light could be just about anything - and a lot of those things aren't serious. Some cars, the light'll come on if you forget to screw on the gas cap. The dash short circuiting is the only weird one you described.
The best way to stop being worried about every noise is to learn about cars and how they work. It's intimidating at first but when you get right down to it, cars are pretty simple. If you can figure out how to undo a bolt, you can do most car repairs
My wife used to be just like you. Every time a new thunk would appear she'd think the car was about to die. I suggested she learn a few things about cars, and she kinda took it to the extreme. Bought a Sentra, stripped everything off it, then put it back together, replacing anything that was worn. Now she won't even LET me fix her cars. Insists on doing it herself. She's having a ball with it, and never had those "what the hell is THAT" moments again.