Are they correct? - Not really, but you would be understood.
Learning English really confuses me. I feel as though I should give up, it's so hard. I suppose I must continue, so I can pass my English exam.
"I was full. Even so, I had to finish my dinner!" - This one is fine. It means you'd had enough to eat, but still had to clear your plate.
I tried so hard to fix the relationship with my friend. We still haven't [kissed and] made up, I need to try harder.
Hope this helps.