Penis tip doesn't get hard

[Corvette]

I've not been on here in quite a while. I had a trial of different syringes with different strengths of Bimix for about 18 months and I didn't do a good job of working through them or of keeping results.
My Urologist has given me a second chance to do the test. I have started, but noticed that the tip of my penis doesn't get hard for about 2 inches back from the tip, the rest is hard as a rock. Makes entry very difficult. My wife has usually had multiple orgasms by alternate methods and is very wet but I still can't enter her. We even use dildo's, so she's not that tight by the time it gets to be my turn.
Has anyone else had this problem and is there an answer for stiffening the tip. It's something that I've never even thought about or remember having encountered.
Thanks

[tomas1]

I don't know if this helps me in that regard, but I have my best erections after taking 25mg of Viagra a while before injecting.

[Corvette]

Tomas, that makes sense cause it would encourage more blood flow. Thanks

[Eugene]

My little guy's head does not get hard when using Edex or Trimix either. Most of the time I get a very hard erection when I inject, but never have a hard headed glans. The only time I can get a hard glans is when I use my VED. I use the VED 75% of the time and only about 25% of the time do I inject.