You will be surprised to know that most of the anti-anxiety medications including Paroxetine may in fact cause anxiety and tremor in the beginning of the treatment. That is why it is always advisable to start from very low dose and gradually build-up dosage of the medication when treating anxiety disorders. The first thing you should do is to decrease the dose of Paroxetine and increase the dose of clonazepam. If it doesn't help you, then, may be you need to change to some other medications i.e., Escitalopram, Sertraline, etc. Do consult your local psychiatrist, in case of emergency.