It can be hard to ask for help because it is embarrassing when we feel like we are not succeeding but I would let most of your teachers know about your dilemma. I say most because by this point in time you are probably aware of which teachers are sympathetic. Good teachers do what they can to help their students pass. They might provide tutoring or extra credit that will enable you to graduate. If one of your teachers is unfair in a way that could jeopardize graduation, perhaps talk to a school counselor, headmaster or some other school figure that can intercede.

Don't worry about your later life. Just figure out how to graduate--you do not want to go through this again. I have seen many students who did not get good grades make a very good living later (including kids from my son's generation). I think school grades are a good predictor for how you might perform in college if you immediately go. However, not everything we learn in school applies to real life. In the US, the people I know who make good livings without college are in the trades (construction, auto repair, etc) and/or own or work in their own (or their family's) business. In the high school I went to (admittedly times have changed) less than half of the boys went on to college. They tended to work on their parent's ranch, in their dad's backhoe (a type of construction) business, enlist in the military, etc.