I don’t post here often, can’t even remember the last time I did. However I’ve been doing TRT for 6 months now. Did a google search on injection site pain and found some threads here and the sticky.
Was feeling more drained at the end of the week. Switched to 2/wk injections instead of 1/wk.
Switched to 26g 5/8" needles instead of 25g 1". I’m sure smaller needles and less volume into the muscle reduce pain, duh. 
Switched to 4 sites rotated instead of just the quads where the doc showed me. Found it is no prob to self inject to the glutes.
I appreciate having the info of experienced folks out here, so I just wanted to get on and post a big “THANK YOU” to those of you who have contributed solid info to the stickies and other threads.