Sounds like you're in the UK judging by your course of treatment reff...?
I'm not going to go all technical for you, but all I can say is that they moved me from Sustanon (weekly injects) to Nebido (monthly injects) over a year ago - it's totally changed my life!
I know of some Nebido takers who only have to inject as little as every 12 weeks to achieve steady state T levels within range. Personally this didn't work for me and fortunately my endo has allowed me to inject at home with the help of my wife and my monthly protocol now means my levels remain at the top end of the scale.
Nebido has little to no pip (pain after injection) and I have never once had any difficulties with or after the injection. It is essential that someone does it for you as the injection needs to be done slowly over 3/4 mins to allow the large volume (1000mg/4ml) a chance to disperse. So if you're anxious about it, your district nurse would be able to administer it for you.
My doc explained to me that because Nebido treatment involves much less peaks and troughs and the steady state period is longer, E2 levels do not fluctuate, I have had no E2 issues on my treatment.
Like I said, Nebido has been a life changer, for me and my family, I strongly suggest you get over your fears and try to look at the positives that may come out of this treatment.
Good luck!