drive line vibrations?

So, I removed the driveshaft (2 piece) to replace my center support (carrier) bearing. I made a very unintelligent decision and did not mark anything, figuring there would be that extra wide groove on the splines so everything would only go back together one way anyways. well, that was true for both parts of the drive shaft but not where the drive shafts insert into transmission. So, I winged it, and now I noticed there are slight to moderate vibrations as well as a loss of power (the engines working harder and producing less speed) while driving. the worst being at 30 MPH in 3rd gear as I'm assuming the driveshaft isn't in sync or balance with whatever it needs to be with. My question is, how do I get the shaft to matchup with the transmission correctly again since I was an idiot and did not mark it?

2000 s10 Xtreme 4.3 5speed