You didn't go wrong. Some lessons have to be learned as an adult. I strongly suggest you find a way to let go of the guilt. You have done your job as a parent. Now it's time to let go so she can find a way to grow up.
You no longer have legal and social responsibility for your daughter. That is hard to hear and even harder to let go.
I talked with a counselor to learn how to deal with an adult child living on my home. My nearly 18 yo granddaughter has been living with me for 3 years. I worry about health issues. Her health is her responsibility.
Parent's have to let go to allow their child learn from their experience. We're entering a different stage of life. It's hard for parent and child to change, to let go of our power and for the teen to realize that they have more responsibility. As a parent of an adult teen, we can require that they follow house rules. House rules are what occurs in our house and to us.
I suggest your daughter is rebelling in an attempt to separate from her parents and to see where the boundaries are. This is a necessary step on the way growing up. You're in a power struggle with her. As we learned during their time as a toddler and again when they were in early teens, everybody loses. Their are no winners.
Your daughter's anger will increase as your anger increases. My daughter and I struggled for several years to find a balance. When she was 20 she had a baby. Even tho she had her own home, I still thought it was my responsibility to continue teaching her. We often fought interspaced with hernot talking with me. Gradually I was ableto let go. Both ofus were I counseling to get help getting past our anger. Before baby was born I told herthat she had to move out and begin her family. she was relieved and immediately moved out.
I suggest that when we as parents, frustrated and still feeling responsibility, get angry on an attempt to prove that we can see the kids making poor decisions and feel responsible for getting them back to what we feel they should do.
Once our child is 18, we have to let them learn the hard way. It's time to be adult and let go. It's time to accept we've done our job raising our child. To accept that the only thing over which we have control is ourselves and our home.
I found that once I nearly completely stopped trying to control my daughter and now my granddaughter, they were respectful and did follow the few rules I'd made they stopped rebelling and even asked me for my opinion now and then. When I walked away and didn't tell they eventually stopped yelling. We dohave a choice to fight or not fight. When parent's fight with their kids we are unconsciously telling them it's ok to fight.
I suggest by respecting ourselves by not fighting and respecting our child's right to own their own life, we are showing them how to respect.
There is a way to respect each other so that both the parent and the teen can work together to problem solve.
I suggest you look up the web Site for "Nonviolent Communication." I've found "Parenting With Love and Logic" useful in all relationships.
They also have a web site.