Every single relationship will get "boring" after you've been together for ages. Love isn't a feeling, it's a commitment; to love every day, physically and emotionally. It's hard afff, it's not always laugh, smiles and fun. People tend to quit when it stops being cute.
Ohh the sparks is gone." No, that's not how it works. You want somebody to never give up on you and love you unconditionally? Do the same. This isn't hollywood, this isn't romantic every after bs. Love someone when you don't want to, when they are being a fricken asshole.