Why did i still have an anxiety attack while on ativan (lorazepam)?

Maybe it's not great: as a treatment. Benzodiazepam drugs of which ativan (lorazepam) is one are addictive and have potentially nasty withdrawals. They stay in the system for limited times so either they need to be taken round the clock or they won't hit the panic attack. SSRI anti-depressants don't have that problem. Furthermore Cognitive Behavioral therapy works to transcend the panic attacks.

Anxiety : Although Ativan (lorazepam) is used for anxiety it does not cure it. It just alters our perception of what is going on so we may not pay attention to stressful episodes. You may benefit from seeing a therapist also