Even if you take the love potion, there is no garante, that you will be loved back or that your friend does not find your blind love disturbing. What if your friend turns out to be abusive or makes you miserable? Will you still have to love and stay with him/her no matter what?
Let's say the...
It's a bit difficult to answer for since birth, since someone who had a curse like that since birth might think entirely different about the issue than someone who gets it at some point in their life. When your own parents die and it is because of you, then the guilt might just be enough to end...
It's not an exact match, but Code Geass sounds pretty close to that. It's not a novel though.
International warfare? Britannia pretty much wages war against the entire world and in the end the conflict of the story escalates to an international level.
Naive Hero defeats the MC in the end...
I'm also not a native speaker and I don't have much experience yet, but just starting to write is the first step to getting better. Whenever I don't know a word, i just look it up and there are tools out there that can help you with grammar (like grammaly, it's free, at least grammar correction)...