A few days ago, I woke up abruptly in the middle of the night. My heart was beating fast. I felt a sense of terror, but the night was quiet. The worst part of breast cancer treatment was over. I was safe. I got into a fetal position and cried anyway.

After radiation treatment ended in January, I thought the overwhelming fear would end, too, but it hasn’t. I have also been having bouts of crying, difficulty falling asleep, poor concentration and a sense of a foreshortened future. All of which, needless to say, is making it hard to enjoy life.

I have begun to wonder if I’m dealing with post-traumatic stress disorder. The National Cancer Institute reports that like war veterans who find they’re still in a war zone in their minds after they return home, breast cancer patients can experience PTSD. Experts say symptoms usually begin within three months of the trauma, but may not appear until many months or even years later.

Whether it’s PTSD or some other kind of anxiety disorder, my symptoms were on full display on a recent visit to a lounge in Miami Beach. I’ve been pushing myself to socialize more, and I accepted an invitation from a friend to go out.

Over in one corner of the dimly lit space, a group of statuesque women and trendy guys were playing Jenga, a game in which players take turns building a tower out of wooden blocks. A guy I had just met asked me to join in, but the thought frightened me. I pictured the tower collapsing in front of me.

I sat by the bar and watched — and worried. What if one of the blocks injured someone? What if there was a fight and people started throwing them? It didn’t happen, of course. The intimate crowd was as safe as a private party. But I couldn’t turn off the anxiety.

A friend of a friend offered me a drink, but I wouldn’t dare — not with the correlation between alcohol consumption and the increased risk of recurrence. I moved to a cozy couch, but the second-hand smoke made me uncomfortable. I had to stop myself from asking the smoker how he could take his health for granted.

“I’m really feeling awkward,” I told my friend Laura. Her smile turned to a frown of concern.

“Do you want to go? You know, no one can tell that you went through breast cancer,” she said. “You look great. Your hair looks super cute.”

I wanted to flee, but I stayed. I had to challenge myself. My comfort zone for months had been my bed.

Minutes later, I saw on my iPhone that someone had tagged a photo of me on Facebook. I didn’t like it. As I untagged myself, Laura introduced me to an impeccably dressed Russian woman from haute-couture land. I couldn’t hear a word the tall blond model was saying because I was preoccupied with how fat my hips looked in that picture.

The nagging fear has magnified my insecurities. I’m getting used to the asymmetrical look of the breast implants and the horizontal scars, but the patch of skin discoloration from radiation therapy is hard to explain. It looks as if I had fallen asleep while sunbathing topless on a windy day, and a flying handkerchief happened to land near my collarbone. Except the contrast is reversed. How unlikely is that? It is so abnormal looking.

Both the cancer diagnosis and the treatment were traumatic experiences. I still find myself thinking about the powerlessness of being in a hospital bed, and about the pain in my mother’s eyes as she saw my pain. Still, most breast cancer survivors never have a recurrence. The tumor is gone. My body is recovering. Yet my mind seems to be stuck in time.