Baclofen should not be stopped abruptly and I hope, you must be aware of this fact. It should be tapered down gradually over a period of one to two weeks by gradually reducing the dose.
As a general rule, after stopping any particular medicine which can cause discontinuation / withdrawal symptoms, these symptoms usually go away within a period of 7-14 days in most cases. In few cases, some mild symptoms may persist further for a week or two.
Assuming that, you have tapered it down slowly but still experiencing the withdrawal symptoms, most likely, withdrawal symptoms should subside within the next week or so.
However, if these symptoms increase in severity OR you are not able to tolerate them OR they persist for longer duration, you can discuss with your doctor regarding restarting the last tolerated dose and then start tapering it down much more slowly.
Restarting the last tolerated dose and then slowly taper down the Baclofen again could be helpful in controlling the withdrawal symptoms.
Kindly also go through the link to pdf document given below for more information. (Page no. 4-5)
I hope this helps. Please feel free to discuss further if you have any other query.