What does Te quiero más que ayer y prometo amarte más mañana means?

"Te quiero mucho" is Spanish for "I want you very much" i know cause i talk & speak Spanish...

Not exactly. Te quiero mucho translates literally to I want you very much but it doesn't mean that AT ALL. It actually means "I love you very much." This is kind of an informal way to say it. You would use this for friends. For a boy/girlfriend you would say "Te amo"