You'd think that as lifters that practice mental and physical toughness our woes would lie in getting over plateaus and fixing imbalances and correcting flaws, but no, the biggest challenge we face is throwing weight off the bar when we need to. LOL you're NERVOUS about NUMBERS?? Come on man, get your ego out of the weight room.
On a more serious note, when I switched over I had to throw 150lb off the bar, but now it's almost back on. It's all technique I find.
For me personally my posterior was lagging and my adductors were tight as hell. In fact everything in my hips was tight. Make sure you're doing drills to open up your hips like Defranco's Agile 8. I would even suggest playing around with stance width and toe point to see where you best lift according to your structure. I had to rework everything starting with just the bar, and I'm still working out some kinks.
If you want to talk time I would give it around 6 months minimum before you're close to your conventional numbers, I pulled my best conventional weight after 8 months training sumo although I did have a lot of work to do. Some guys can just jump right into it.