It’s definitely not time to give up before you even get your results. Even if you have done poorly, you’ve still spent half a year on it giving up now would effectively waste that.
If you do get bad results then consider what it would take to improve them. Would it take so much time that it negatively impacted on your other subjects? If it wouldn’t then definitely keep trying. If it would then that’s when it’s time to make a decision about it. Regardless, dropping a subject should be your last option, you’ve already put so much time into it, it would be a waste to stop now. However if trying to well means that your other subjects suffer then you could consider reducing the amount of time you spend on it and focusing on your other subjects instead. I still would not advise dropping it entirely though.