A number of summers ago there was a theater production in town, with a great title, "I Love You, You're Perfect, Now Change." It is so true that we tend to do this to people with whom we are close. The intention may be coming from a good place. The other person's behavior may truly be less than noble or even destructive. However, the energy of fixing, of wanting someone to change, and expending lots of energy trying to get them to be different from how and who they are, never works for either person.
Letting go of trying to fix people is a wonderful way to increase personal happiness, to have more energy, and to enjoy better relationships.
Here are a few suggestions for how to refocus your energy
The subtle or not subtle message in the energy of fixing is that there is something wrong with the other person, that they are not enough as they are, and that you know, and they don't. The other person always reacts instinctively to those negative judgments. What do we all do when negative energy is coming at us? It’s called the "fight-or-flight response." We automatically defend and attack, or we run away. Neither of these responses allows the other person to even consider whether what you’d like them to improve is worth entertaining.
The only good time to offer your sage advice is if and when that person asks for your input. Speak from your heart when offering counsel, because heart energy is not judgmental and it creates an environment in which the other person can be open to listen.
For the person who is the fixer, focusing on what is wrong with someone else is often a way to distract yourself from something you need to pay attention to about in your own life and psyche. If you are willing, try on this different perspective: consider that the other person’s unsavory behavior is in your face so you can learn something important about yourself and grow.
If you'd like to experiment with evolving yourself rather than fixing people close to you, reflect on the following questions: If you were not spending so much time and energy trying to get the other person to change (including complaining about them), what would you have to notice, feel and/or be doing proactively in your life? What options are in your control? What choices support your well-being? What do you need to help you go for them?
Keep in mind that people only change when they want to and when they are ready to commit to the work it takes. That part is only in your control if the person who you want to change is you.