Feeling Cheated by My Psychiatrist: Need Advice on Anxiety Medication

I have crippling anxiety, social anxiety and depression. I ran out of my meds (they don’t really work), but I get withdrawals from them. I was telling someone how I won’t be able to sleep cause of my insomnia, and they gave me a Valium to help. I wasn’t sure if it would work cause I’ve never taken it before. But when I tell you, I’ve never felt so calm and at ease like I did that night, ever… I mean it. I got up, and had the motivation to do things I’ve been putting off and it made me so happy! And I slept really well without nightmares!! What’s a good way to ask my doctor about this? Cause I feel very cheated by my psychiatrist right now. She gives me meds that aren’t even for my conditions… like why? What’s the point?