Welcome to the site.
Well if you had abruptly switched over from Ventab Dxt to another drug without tapering the dose of the former drug then it is most likely that these symptoms that you have developed are nothing but a part of Ventab Dxt Withdrawal syndrome but you do not need to panic since these withdrawal side effects are temporary and self limiting and they are most likely to subside on their own within the next few days so you shall patiently endure them.
However if the intensity of the withdrawal symptoms
begins to increase over the next few days or they continue to bother you for the next two weeks then you shall consider asking your doctor to add Ventab Dxt at a lower dose of 50 mg / day and then after 1 week on this dose you shall start the weaning of this drug by taking it at this dose on alternate days for 10 days and then stopping the drug completely.
I hope this helps.