Was there anything stopping Sauron from making another "one ring"? Was he too weak since his separation from the ring to craft another? Or would it have taken a long time?
The quick answer is, "Yes, he was too weak." In Gandalf's words:
Now how, exactly, you want to interpret that might vary. After all, Sauron was certainly powerful enough to "reconstitute" himself, reorganize his armies, and sweep back into Mordor relatively early in the Third Age. But the Ring contained him, in a sense:
(both quotes from The Fellowship Of The Ring, Chapter 2, "The Shadow Of The Past")
Even without the Ring, he still had the ability to control the others: in particular the rings of the Nazgûl. But it's at best highly questionable, as I read the material, whether he had enough power to create another Ring of the same power as the first.
Sauron placed an enormous amount of his own "strength and will" into the One Ring in order to make it powerful enough to dominate the 3, 7 and 9 rings. Although it's not explicitly stated, the fact that he expended vast resources on a search for the Ring over hundreds of years would strongly suggest that making another ring simply isn't an option.
More importantly, the One Ring was invested with sufficient power to rule all the other magic rings in Middle Earth. Since Sauron knows that the One Ring (described in the Silmarillion as a device of "surpassing potency") is still knocking about, if he made another less powerful ring to wear then he could find himself subject to the will of whoever wields the One Ring. That was something he absolutely couldn't risk.