Hello,According to the symptoms you have described- transmission has slipped for some time. This can be caused by insufficient transmission fluid level, it's age, jamming valve block or even failure of transmission electronics. I recommend to have the engine and transmission control units checked for fault codes and transmission fluid checked and changed. Most likely transmission fluid and filter change will solve the issue.Best Regards,Stan
Can I drive the car before I fix the problem?
If it drives as usual and you cannot feel the transmission slipping- car can be driven until first chance to have this checked at the workshop.