As a 30 year old single mother of two, I can say I've been a few relationships. Some, a bit tulmultuous! Some, almost perfect. Never love someone more than you love yourself. No, this isn't stingy advice, when you love yourself, you'll have more confidence in yourself, you'll know your worth, you won't be pressured into doing things you don't want to do for the sake of "love". Low self esteem is something I've struggled with most of my life, and it made me not love myself. As a result, I've been in mentally abusive relationships constantly, because I felt that I wasn't worth anything better. Also, if you love yourself more than the person you're with, if that person leaves you, it won't hurt as much, in some cases you can just shrug it off. It also makes it so you can leave a toxic relationship easier. I'll probably do a post about toxic relationships after this.
REMEMBER: THIS IS VERY VERY VERY VERY VERY VERY VERY VERY VERY VERY IMPORTANT. NO ONE is worth you commiting suicide over. You may feel that that person is the love of your life, and you can't live without them, yes, you can. Trust me. Fuck them. That failed relationship you just had? That person that don't want to be with you...It's okay, there's something better for you waiting.
Take care of yourself <3