"I don’t think I can go through the pain again..."

I have two yearly infusions by a lovely man who has retired.no pain needle in didn’t feel anything...this time different set of people..tried to take my BP twice with an electoral machine wasn’t working, tried another that wasn’t..my arm was so sore..the while an old fashioned machine was sought a nurse tried to get a canulet in my wrist then the inside of my arm to no avail..I was in agony and sweating..the new BP turned up my BP was on the ceiling...that nurse tried to get a vein in my other arm couldn’t..said she was writing to my GP re BP and was going to speak with the specialist to put me on a different drug via twice yearly injections..I asked her to have one last try so I could have the infusion .yes she managed to get a needle in the inside arm but hurt so much taking it out I did bleed too. Rang her when I got home and said I don’t want to change meds..never came back to me...also saw my GP she checked my BP I also did a weeks reading and nothing wrong with it..the pain I experienced prior was more than enough...even GP said the same. I am scheduled to have two further yearly infusions but very reluctant ...why didn’t they do the back of my hand as normal...or has that changed as well...I am in a quandary can you advise..why change something that was working ..??BP not done previously all paperwork and information was there should not have to go through it again.