'37M' '40W' 20-NB Months later, I'm still wondering if I made the right decision by ending my relationship after my ex's cancer diagnosis.

TL;DR: I broke up with my girlfriend after a long and emotionally difficult situation surrounding her breast cancer diagnosis and treatment decisions. I felt increasingly excluded from her choices and overwhelmed, especially as she rejected standard medical treatment and our communication broke down. Even months later, I’m still unsure whether leaving was the right decision or if I gave up on her too soon.

I'm a man in my 30s, and even months after the breakup, I keep replaying everything in my head. I honestly don't know whether I failed someone I loved or whether I simply reached my limit.

More than a year ago, my then-girlfriend found a lump in her breast. She went to see a doctor, who strongly recommended that she get a mammogram. What I only found out much later was that she refused it, became very upset, argued with the doctor, and left the hospital in tears. At the time, she told me everything was fine.

Shortly afterward, she left for a long trip through South America. She ended up cutting the trip short and came back home. She told me she only needed one routine follow-up appointment. After that appointment, she told me she had been diagnosed with breast cancer.

From that moment on, I tried to support her as best as I could. My father died of cancer, so the whole situation was deeply personal for me. I encouraged her to follow evidence-based medical treatment because I was terrified of losing someone I loved again.

She told me that standard chemotherapy was not an option for her. Instead, she visited a spiritual healer and also looked for doctors who offered gentler forms of treatment. I respected that it was ultimately her body and her decision, but I was deeply worried.

What hurt me the most wasn't only the treatment decisions. It was that I increasingly felt shut out. She often made important decisions without involving me, and I frequently learned about major developments only after the fact. I felt less like her partner and more like an outsider.

Eventually, everything boiled over. We had a huge argument. I raised my voice and told her that I believed she should follow the standard medical recommendations because I was scared she was putting her life at risk. She responded by telling me that I was too weak to go through this with her.

That sentence broke something inside me. In that moment, I ended the relationship.

After the breakup, her parents also cut off all contact with me.

Now, months later, I keep wondering whether I abandoned someone when she needed me most. At the same time, I don't know what else I could have done. I couldn't force her to accept treatment, and I felt like she had already pushed me out of her life emotionally long before the breakup.

Was I wrong to leave? Should I have stayed despite everything? Or is it understandable that I reached a point where I couldn't continue the relationship?

I'm especially interested in hearing from people who have been through cancer themselves or have supported a partner with a serious illness. I'd really appreciate honest perspectives, even if they're critical.