Arguing with myself

I know my last post said a lot about forgiving others and not judging...but dang, it's really hard to stick to that. I still 100% believe in living like Jesus did and forgiving 7X70 times (which equals 490 times), but what if someone wrongs you 497 times? Lol...just once more after 7X70? Can we take Jesus literally and ONLY forgive them that many times? Because I have someone in my life who has breached that point...I'm trying my hardest to remain loving and forgiving to this person, but I'm at my breaking point. Can I just tell this person to stay out of my life? Forgive them for this last injustice but then choose to have nothing else to do with them? Isn't it better to distance yourself from someone than to allow them to bring your character down? I don't like the person I am when this person is a part of my life. Granted, some of the happiest moments of my life were with this person, but the most devastating were also due to this person's hands and actions. I have forgiven. I am unable to forget. And I think, I am unable to keep trying. I know Jesus wouldn't and hasn't given up on this person, but I am not as strong as Jesus. I've done the best I can do to show this person God's love and forgiveness only to be walked on...and in those moments, I've shown this person the non-Christian in me. I'm ashamed of that. Is it selfish to want to better myself instead of continuing to try and help better this person? I know love is long suffering...but I'm really discouraged right now. To just get this person out of my life would be such a relief, but I'd feel like I failed God. On the other hand, I know He will forgive me when I fail Him. What should I do? I can give it to God and hope He can use someone else to change this person...because I'm doing Him no good if I continue on this path...forgive me....