Just something to keep in mind in the spirit of "this isn't for me"- this isn't for everyone. Never consider it a knock on your intelligence, courage or character if you discover that you don't find advantage play to be a worthwhile use of your time. Ask around a national laboratory or NASA facility how many people spend any time in casinos. These are the smartest and most capable people in the world and you won't find many card counters among them. Maybe not any, they're too busy.
The swings are real and inevitable, and losses of hundred of units or more are completely to be expected and are a consequence of the same mathematics that allows us to play with an advantage in the first place. No free lunch. You have to be a bit of a masochist to be willing to endure this, but like traditional sadomasochism, it has its rewards. If you have religious faith, it helps to acknowledge that the same Divine Architect that lay the line on the orbits of electrons and planets and keeps them stable, also is responsible for the laws of statistics that guarantee you will get your money back if you play right, and last long enough.