I've also struggled with poking myself with the needle, mostly because of the initial pain, but also because I have a tendency to get lightheaded and queasy when it pierces the muscle. This is what I've found helpful:
1. Giving myself a little pep-talk right at the point that I'm ready to pierce the skin, something like, "this pain is for all the brothers out there right now going through way more pain right now. If they can handle it, I can handle this."
2. Gently touching the needle to different parts of my injection area, to find a spot that feels a little more numb than others.
3. I haven't tried this, but now that I'm thinking about it, having a show or something on at the same time that's a bit of a distraction.
4. I also squeeze a bit of flesh on my thigh before I inject and slowly let it go as I'm injecting.
5. Keeping the needle at a steady angle (usually 90 degree) during injection, so as not to have it move too much once it's in the muscle.
Hope that helps.
Best of luck to you!