Afraid of affection, sex, and afraid to be comfortable

Being so afraid of compassion is definitely not normal, right? It seems that whenever I have a period of time where I'm happy and begin to feel safe within my relationship I suddenly relapse.

Affection and love from my partner begins to feel threatening. And I start to wonder if they are seeing someone else because I'm not used to having someone care so much about me.

These feelings leads me to scour the Web for "signs of cheating" and I end up trembling and crying if anything on those lists even remotely resembles what they're doing.

I've only known pain, deceit, and betrayal, so whenever she shows me any sort of affection, emotional or physical I begin to doubt and grow cold.

Sex is triggering for me as well, because during those moments I'm left vulnerable and I start to feel as though maybe I'm not the only one, and that if I'm not surely there's someone better.

I don't know what to do. These feelings came back last night. Her phone had been having issues and when we finally got to talk on the phone, she began telling me how much she misses me and how much I mean to her. Which lead me to remember what that list said, how random bursts of affection is a sure sign of infidelity. I hardly slept last night.

I don't want to confront her because there is no evidence, only my own thoughts and "gut feelings". I'm just so terrified of getting hurt again, that when she was being affectionate I acted distant and cold.

This isn't normal. But yet I feel like maybe a life of loneliness isn't so bad. At least I'd be trigger free.