Has anyone tried the amino acid GABA for anxiety?

I have been reading about it and it sounds like what I need (if it works!). However the recommended source was Solgar and they have discontinued it.

Has anyone any information on or experience with GABA, and if so, can you recommend a UK brand I can get.

I have emailed Solgar to see if they can tell me why it is discontinued. Any experience or info any of you have would be of great help.

ALSO,

Is anyone using Valerian - if so, is it good? What are the positive effects from it? Are you using it in conjunction with Passion Flower, and can you buy the 2 remedies as one supplement?

And can Valerian be used with St Johns Wort?

Thanks, Caroline