It's good that you're raising your grades, but what you have right now is pretty terrible. The amount of effort needed to receive Bs in public school classes is definitely worth not having to bag groceries for a living. I've always been a person who doesn't have to put in as much work to perform well on school work, but you could easily pass all your classes with As and Bs by putting in an extra 20 minutes of study time per night for each of your classes. Even if it seems like a lot of time to spend, you won't regret it when you're 45 and not mixing concrete for a living.