Just remember that each individual has their own unique healing time line. Try not to compare yourself to others (I realize that's virtually impossible)
Prior to surgery ED was never an issue.
It was 11 months post surgery before we had a really usable erection (with Viagra). The 11th month was such a turning point.
Prior to that, my husband used the pump for a while, and tried the injections. The injections were awful--very painful, and thus unsuccessful. We did everything to stimulate the blood flow.
Just remember that if you take Viagra, be sure you have an empty stomach---that made all the difference.
Again, everyone is different, be patient, try to relax as much as possible and good luck!