Yeah i had the same when i started TRT. It was the strongest when i was allowed to do injections at home. First few home injections went kinda badly and had severe PIP(post injection pain) and that created the hesitation.

What helped for me was to minimize muscle tissue damage and over time the hesitation diminished, unless i try to inject into ventrogluteal site. Never figured that one out.

• Using a smaller gauge needle, from 23G to 25G.
• This limited the rate at which i could inject too and that reduced PIP as well.
• Lowering the volume of med injected, though had to balance that with higher frequency of injections.
• Keeping around 24H between leg training and injection. Last time i trained legs right after injection and my glute(ass) was in debilitating pain for a week.
• Never reusing the needle. Once it already went in it's dulled enough. Like stabbing it in half way and then pulling out. Not trying again with the same needle, but switching it to a fresh one before trying again.
• rotating sites. Currently left and right glute, seems to be enough, but if I'm ever going to venture into steroid territory then i probably have to add in delts as well.

Of course it took some hesitation even after that, but as each fix reduced PIP. The hesitation slowly went away.