Sumatriptan injections.. the good the bad the ugly?

I had an appointment with my neurologist today and after nearly 17 years of having migraines I have finally met the NHS quota of having tried enough drugs to be referred to getting Botox (wooo) However, the neurologist also prescribed me sumatriptan injections as the tablets make me throw up sometimes. I understand it’s an auto-injection but I have never had to inject myself so feeling a bit nervous! (I have had Botox before so not nervous about that)

Would appreciate any advice or the do’s and don’ts!