So, while you're reading the stickies, I'll hel[p you out.
You can use a smaller needle. I use a 25 gauge 1" needle to inject IM in my glutes, but I'm relatively lean. You can use an insulin needle and inject subq and that will probably be even better (I don't like subq, but I'm not the norm).
Yep. It gets better over time - I don't get sore at all.
OH MY GOD YOU'RE GONNA DIE - jk, it's normal.
It's different for everybody, from a week to six weeks. By six weeks, you're getting the full dose (based on half lives and shit) and should feel good, but you will continue to see improvements in body composition and other stuff for a year or more.
Well, you're in the right place.
So, the dose you're on is pretty high, but don't get all freaked out about the estrogen issues and shit. You should be aware of them, but it's not all doom and gloom. Testosterone converts to estrogen. If too much converts, you begin to get all cranky and shit, and, possibly, grow breasts (extreme case). So, you'll want to get your E2 checked after six weeks and see where you are. Around here, people consider 22 to be the ideal, and a lot of guys need an AI (aromatase inhibitor) to prevent the conversion and prevent high estrogen levels.
Other guys don't need it. I have been on TRT for three years, have never taken an AI, and my E2 levels are always borderline low. You just need to find out what works for you.
If you want to have kids, or like your nut sack full, then take hcg. If you are done with kids, don't want them, and don't have your self image tied to the size of your balls, don't. Personally, I don't like it. It makes me hold water and feel funky. And, I get tired of my balls dropping in the water when I'm taking a shit. So, I don't take it.
Finally, you should figure out the cause of your low t. You may be able to fix that and get off trt. @KSman can help with that, but you need to post all of your labs to get his expert help - and he is an expert.
Good luck brother.