Yes you probably did start to break up a mass of congealed bile and this has blocked the gallbladder neck. Before the flush it was probably lightly compacted into a single block. Effectively you have been depending on liver bile for digestion and this is well known to cause reflux type symptoms. The right side pain is the giveaway that you gallbladder isn't contracting fully.
This can happen to people who have biliary sludge and carry out just one liver-flush. The instruction are quite clear; you should carry out a program of liver-flushes every 2 to 4 weeks.
You should prepare to flush again and if you can tolerate to protocol it may be advantages to increase the quantity of olive oil and lemon juice if the sludge is stubborn. If the pieces of sludge are large one needs a powerful protocol.