@Nicolien2 Sorry that your first hosting experience was so negative. It's really unfortunate that some guests don't take time to read and understand the listing before booking. Your listing seems extremely clear in terms of what the guest can expect if they stay.
I would try contacting Airbnb again, maybe message them on Twitter @airbnbhelp to ask to have the review removed. It may not work, but perhaps worth a try if you haven't already.
Honestly, I wouldn't let one bad guest sour you on Airbnb. You say that you have some other guests booked, and if they review you positively, your reviews will soon be looking up. I thought that your response to the guest was good as well: it painted you in a positive light. You seemed calm and professional, and you drew attention to the fact that they obviously didn't read your listing. If I read what they had written, it would likely not put me off staying with you (although I might ask for a spare heater).
If you want to quit Airbnb, it's your decision, but I wouldn't let one bad guest wreck it for you.