Its a bit concerning that you have medication for anxiety and only take it 'sometimes'...if you have been perscribed anti-anxiety or anti-depressants then you have to take them every single day for them to work.
You can try natural remidies such as St John's Wort & Vitamin B Complex though I have tried these for a year with just a little affect to the overall problem.
Best way is to seek therapy address why you have anxiety.
A pill is not the solution to everything trust me
