Yea ! Men are mostly just hairless apes, you'll understand perfectly when you learn to read our grunts. UUH uuh uuh ee ee...
It does sound like he is feeling insecure and afraid of losing you. And you ladies are right, we are lousy in words when expressing feelings, especially with love. He is kinda making promises that he will try to improve and make things better. He is vouching his loyalty and hoping for some reassurances.
I wouldn't get hung up on the "spark" thing too much. It's just a meaningless grunt. UUH uuh