My guess? You had some sort of transient event (steam hammer?) that pulled your system.
So now your line is "sprung" - it is unable to return to its operating position because some of those Y supports are now acting as line stops. Without knowing the added load that your system is currently holding and because of possible yielding, there is little chance that you can estimate the load distribution.
One thing you could try - define displacements (replacing the restraints) at all those points where the pipe is newly restrained. You might be able to recreate the deflected shape of your system.