+1 to having someone there who can help support you (for me other people being around made it worse, so I did it alone, but it was good to have someone nearby in case I fainted).

Also can confirm I would get so scared I just physically couldn’t do it - this still happens to me sometimes. I find it helps to have eaten enough food just before (as well as hydrating significantly) - this is grounding and helps reduce chances I’ll get faint or mentally struggle as much.

And also can confirm it gets easy over time - now it’s no problem at all, I inject once a week and it’s almost never dramatic or painful.

Also, might be good to have a little towel nearby in case you have a little blood come out - it didn’t always happen, but early on I started with injections into my thigh, and my thighs are very vascular and I frequently would bleed from subq injections; now I inject in my belly (which was mentally something I had to work up to), and I have far less bleeding. Either way, just have something to catch a drip in case it happens.