I lived through the process of my father ruining his relationship with my mother and ultimately messing up her life. He eventually became a recovering alocoholic but the damage was done. A few years ago in his latest stages of cancer he told me that he was sorry about how he and alcohol had affected my mom. He admitted that she started out as a happy, joyful, fun, good person. At the end she was sad and defeated. To my surprise, my dad also admitted doing this same thing to another partner after he and my mom had divorced. I never knew about that relationship.
What seems like a lifetime later, I began to see my drinking affect my relationship with my lovely wife. We love each other dearly but alcohol was seeping its way into my life and our relationship. I started to sense it but she confirmed it by confronting me on a couple of occassions making it clear that this was not ok. I am grateful that she did that although it was and is up to me to fix it. I took steps and will continue to take steps to deal with my issues. Things are good again between me and her and I get to continue enjoying this God-given relationship. I am grateful.
The "cycle" can be broken. I do not have to repeat my fathers behavior. I will not.
You certainly are not alone in your mistakes. Nor do you have to be alone in your recovery and future successes! There is time and hope for healing.