I only inject in my delts for the same reason, i find it very hard to reach around and inject and aspirate in my glutes, its almost like im too unflexible lol, i manage 2ml in delts and i think i can take more, theres never any pain after or the next day, i inject my 2ml of oil over 60 seconds, go very slowly, breath and try to keep calm, im in the middle of a cycle and my first injection in 3 years and inwas nervous too, just relax and breathe.

What gear you running?