Dealing with background chatter is probably the most difficult aspect of any kind of meditation practice. This is especially true if you are feeling distressed for any reason.
When this happens, realise your mind has wandered, note what you were thinking when your mind wandered, then gently, without self-judgement or criticism, bring your mind back to the focus of your meditation. If you are practising a guided meditation, just continue from where the CD or tutor has got to.
When you loose concentration, just persevere. When you lose your concentration and find yourself being led by background mental chatter, just go back to 1 if counting the breath, resume focussing on the object of your meditation or tune back in to your guided meditation. DO NOT CHIDE OR JUDGE YOURSELF FOR THIS. We are hard wired to think backwards and forwards, and it takes practice and perseverance to stay in the present for any time.