There are a few reasons why we go on insulin. For me it's because my pancreas doesn't create but less than 1% of what my body needs. Talk to your dr. and ask why YOU are being put on it.
Insulin shots are WAY WAY different than a "regular" shot. I haven't had a regular shot in at least 10 years. I HATE SHOTS. But the insulin shots I rarely feel and when I do it's less pain then a sticker. Honestly, I'd tell you if it hurt. Sometimes it can sting a teensy bit when I first start to inject so I move it a bit and find a spot that I can't feel it at all. I always inject in my tummy (I'm a big girl so there's more padding and it's the easiest spot to get to) but if I'm in the hospital I take it in my arm.. Doesn't hurt there either..
Use a new needle every single time and no need to pinch. The needles are tiny and you can do this. I'll tell you like I tell all the scardy cats.. GET OVER IT. Not being rude, just saying you want to live a HEALTHY long time right? So you have to put your health before your fear. Besides conquering your fears will give you a sense of pride and accomplishment. Seriously.
So do what you need to do.. As for the financial aspect.. If your dr. wants to give you the $300 or more dollar a month insulin tell him you cannot afford it. There are plenty of alternatives that are affordable. I think even many pharms have insulin for under 10 a month. Also many insulin companies offer ways of helping you pay for it. I'm on the PEN insulin which would be very expensive but my insurance pays most of it.. However, my son's dad has no insurance and he is on insulin.. He pays a few bucks a month for his.
Best of luck in self treatment. I know once you do the insulin a few times you'll get the hang of it and see there's no real pain to it.