A word of caution about generally crushing up tablets and trying to put them into capsules. Unless specifically stated in the summary of product characterisitcs of the med, chances are you could compromise the integrity of the drug. This could lead to less than the intended amount being available for absorption and hence dose failure. The capsule may break up in the stomach, exposing the contents to gastric acid environment and hence destruction of most of the drug, or the med itself could cause gastric irritation. This is just one such thing that can occur. Also, if it's a slow release preparation, (Xanax can come as this) then you can potentially run the risk of dose dumping whereby instead of a steady controlled release of the med, the whole payload is delivered which could excedd the intended therapeutic leves and so may lead to a potentiating of side effects.
With so many factors by doing this you can't guarentee of acquiring the intended dose levels.
If you can't tolerate the tablets, there may be available Alprazolam as an oral solution, or orally dintegrating tablets which may help to overcome the bitter taste and and also to help ensure correct dosing and so hopefully symtpom control.