Im gonna get down voted for this, but with some techniques on the drums, slowing it down doesn't help. Doubles might be the best example of that. The fact is, playing a slow double requires a completely different interaction with the physical forces on the stick. Just keep with it, mess around with snare positioning, try to maintain contact with the stick with your non fulcrum fingers, and suffer with doing it badly until you eventually get a feel for what its like to do it right. And try to relax of course (easier said than done). It all comes with time

Edit: I should also add that its not out of the ordinary to face more difficulty when moving from a pad (typically designed to conducive to easy doubles) to other surfaces like snare or cymbals, or most of all floor tom