Help me!!

How do you know that your significant other is the one? I've dated this guy for 2 years and I thought he was the love of my life but I realize he didn't treat me right now and got me into horrible things. Now I'm with this guy for almost 5 months and I'm more in love with him. He treats me right and every time I look into his eyes; I know I'll be safe and be okay! But how do you know that someone is the one?