Voicing the rolled R

[BlueWolf7]

Hi,

I have been working on learning to roll the R and have gotten to the point where I can get it unvoiced for around 2 seconds at a time.
My problem is all my energy and breath is going to getting that when I try to add voicing I either stop the vibration of the tongue or the voicing isn't consistent so it doesn't sound right.
It is really frustrating because I can get the movement but every video I watch on youtube say "now that you have the vibration...just add voicing" but no one explains any tips on how to get that to happen. I find it very difficult like I said because it is already a lot of effort to make the unvoiced rolled R. Anyway, any advice would be great.

Thanks.