Definitely want a pump. I had my RARP probably around the same time as you (mine 9 March), but I'm several years older. Luckily I don't have much of a reaction to Tadalafil, but it certainly wasn't doing enough to get an erection (I only had nerve-sparing on right hand side, so I'm not overly surprised at there being a problem). I started on a pump around 2 weeks ago and it very definitely helps. Shame they are no longer on the NHS.
My youngest brother, who is your age, has ED for different reasons. He tried the injection, but was in agony for hours afterwards, which has rather put me off (or put me off even more would probably be accurate - I'm happy to stick a needle in most places, but I'm not sure about old todger!).