I've replied to a couple post's about this, as I was having the same trouble a few months ago. I'm 3 years on T, first 1 1/2 years I had Dr injections, then for the next 6 months I was literally fine with just "stabbing myself". I don't know what happened, but one day, I couldn't bring myself to just jab it in. I counted, breathed, and nothing. I came on here asking for advice, and got some GREAT advice, that I'm still using to this day. If I wasn't so lazy I'd go back to the threat and find the HERO who gave it to me.
Basically he/she told me to ease it in, slowly. Which when I first read it, sounded EFFIN crazy! I really was desperate for advice, so tried it, and it worked like a charm. I've been doing this the past 6 months, and have no problems at all, anymore. I usually turn on some music (or any background noise) sit on the toilet seat, find my injection site, place the needle point where I'm going to insert, and pull the skin tight with my fingers (about an inch in width, with the needle in the middle of my fingers), and ease it in until it's actually inside my skin. Then release my fingers (so I'm not spreading the skin tight anymore), take deep breaths, and push it in, until I can't see it anymore. It still kind of messes with me watching it slowly disappear inside my leg, but it's painless.
It's definitely different for everyone, but this has really saved my T injecting life. I hope you figure out what works for you.