Relationships are a vital part of life. People are naturally relational creatures and designed to depend on other people. We go to others when we need help, when we're lonely, when we want to have fun, and for many other things.
Relationships do not only mean dating. The world relationship is broader than that. You have relationships with your friends, coworkers, significant others, teammates, and family members.
If there is one piece of advice I can give you regarding relationships, it is this: stop comparing your relationship to others.
Stop comparing your relationship with your parent to your friend's relationship with their parent. You are different than your friend, and not everything is nice as it seems.
Stop comparing your friend to another friend. All of your friends are different and play their own different role in your life, and it is not fair to compare them.
Stop comparing your current significant other to a person you used to date. You are not dating that other person anymore for a reason, so don't disrespect your significant other by allowing thoughts of a past dating relationship to hinder the progress of your current one.
Just because your relationship is different than another doesn't make it any less valuable. Your relationships will be healthier once you realize that different variables play into each and every relationship that you have with someone. Every relationship you have is supposed to be unique, and is supposed to bring you different kinds of blessings and lessons through them. If all of your relationships were the same, what would be the point of having more than one?
The grass is not always greener on the other side. If you are consumed with wishing your relationship was more like someone else's, you will not be able to properly enjoy and learn from the one that you're in.