Hey Milan,
The smallest kit that has saved me more than once is a headlamp, a lithium jump starter, a compact 12V tire inflator, a tire plug kit, & a simple pencil tire gauge. Last month I pulled a screw out of my tire on the shoulder, reamed the hole, pushed a sticky rope plug in, trimmed it, then inflated back to 35 psi and drove 15 miles to a shop. A jump starter means you do not need a second car, and it also charges phones in a pinch. The headlamp beats a flashlight because you have both hands free when you are under the hood or swapping a wiper. For messes and comfort I keep baby wipes, a roll of shop towels, and two 16 oz water bottles that I rotate every few months. A tiny first aid pouch with adhesive bandages, a few 4x4 gauze pads, tape, antiseptic wipes, and ibuprofen covers most small injuries. Nitrile gloves, a cheap rain poncho, and an emergency blanket live flat under the spare tire cover. A multi tool, a small roll of duct tape, a handful of zip ties, and spare fuses solve a surprising number of minor fixes. Add a USB charge cable with a 12V adapter, twenty dollars in small bills, and a reflective triangle so you are visible if you have to stop at night. I keep it all in a shoebox size bin so it does not rattle, and swap seasonal extras like an ice scraper in winter or sunscreen in summer.
