Until Covid, I had having MS related b12 jabs in my arm every month. I stopped because they weren't essential for me. I also get annual flu jabs. Anyhoo, I'm a "getting a jab" veteran of some years.
These tips might help when you eventually get the vaccine.
First - relax your arm as best you can. Shake it a bit first if that helps.
Second- take a deep breath and try and breathe out long and slow as you are jabbed - make a woosh noise if that helps. The needle is uncomfy but so is any stuff as it goes in so make it a long "wooosh"
nurses don't care about that comedy noises you make.
Third- ask for a little plaster on the jab site.
Points to remember: it's in the muscle of your arm. Sometimes it's a bit painful to get a jab there and sometimes it isn't. Everyone experiences it differently every time because we are all wired differently. You are not a wimp if it hurts. You are brilliant for getting it.
Thank you for doing it.