What will be your excuse now?

There's no room for excuses. If you tell someone you'll be there for them always, then you'll stick with them through thick and thin. You don't seem to understand the meaning of unconditional love or making a commitment. It means you'd never abandon the one you love and give up on them because you believe in them. Your excuses are only for covering up your lies because you don't want to look like an unreliable piece of shit.