Teachers shouldn't have to give you extra work for you to be successful. As a teacher I don't give "extra" work to those who don't do their "regular" work, and it seems to me you didn't do your regular classwork.
It sounds as if your school year is over. If it is you need to look into summer school. Summer school will give you the credits you need to rejoin your graduating class. Otherwise, next year, you will be a freshmen again.
Sometimes a school system won't offer summer school, but you can take it at a system near yours for credit. Most summer school programs don't start until July and usually run about 3-6 weeks, depending on the program. You need to research this ASAP!
It seems to me as if you just didn't try at all. After all, your message is well written so clearly you are intelligent enough, you are just not working to your potential. If you are truly struggling in a class you need to tell the teacher! They are not mind readers, and unlike middle school they have a lot more students to worry about. In high school you need to take care of, and keep track of yourself - only you can advocate for you.
Good luck!