To me, this is kind of like torturing your kids into being football stars because you play football really terribly -- but you always dreamed of being a star football player. In Spain, however, it seems to be a favourite way of trying to get kids to speak English.
Know what? It doesn't work.
In English, this is called stage mother syndrome, and we don't think much of it. (In Canada, it might be called "trying to get a pig to sing"; it's futile and all it does is frustrate you and make the pig angry.)
Folks: if your kids do not ask you, bother you, demand English classes from you...please. Don't do it. I don't care how smart or bright or intelligent your kid is. If your kid hates English and does not want English classes, don't give them private English classes. Students who are unmotivated are, generally, students who will not do very well because they don't CARE enough about learning and it won't be important for them to do a good job. That is just as true of adults as it is of youngsters. Unmotivated students who don't want to do a good job won't do a good job. You're wasting your money. Your kid will just be angry and resentful, especially if your kid KNOWS you're making him or her do it because you can't. And it won't make up for the fact that you can't speak English as well as you want to.
If you feel self-conscious about your ability to speak English, well, then....I would like to invite you to take classes. I'm not saying this to increase my business. I'm saying this because there are already too many pigs who can't sing in this world.