I'm sorry you are sad about this. You may have "wasted" your time with bad relationships, but there is no way to know that for sure. Don't beat yourself up about it. There are many women who are single for many different reasons.

Marriage and children can be joyous, but can also be a living nightmare. My daughter is 45 years old and for her entire life since her teens has been a hell of alcoholism, drug abuse, jail time, mental hospitals, violent relationships, etc. I don't honestly know if i had it to do over if I would have her.

If seeing your friends who are married on Facebook makes you sad, you can unfollow them. You don't have to unfriend them. That way you don't see their posts everyday, but can still check in on them when you want to.