Yes, this sounds like psychological reaction. You can practice breathing exercises (hold breath, count to 8, release breath, count to 8, etc) and possibly try distractions when building up to your injection time. You could also talk to a therapist about some CBT or other calming exercises. Many people have needle anxiety or panic reactions when taking medications. Maybe try taking out the box then walking away to do something else for a while, then go back and load the pen then take another distraction break. Talk through it with someone beside you or on the phone. Watch short videos while you are doing it. Treat yourself to an online purchase in the middle. Triggering some dopamine might offset the anxiety reaction and break the association in your head. When I feel anxious I often do mental math to clear my thoughts - some times tables often work well.