Mixing Xanax and Valium?

For the first time ever, I started taking Benzos about a month ago--for VERY bad anxiety. I was taking 1mg Ativan in Dec or so, then I was switched over to 1mg Xanax and had been taking that twice daily until 2 days ago. So about a month or a little less. At 1mg twice daily I was feeling like my normal self and even better than normal.

My dad is an addict and slowly picked off my Xanax, like he would take some of my pills, so I was left with taking 1mg to 0.5mgs the last two days as I only had a few left. With the lower dose 1mg or .5mg I began to feel my anxiety again. Within twelve hours of taking only one .5mg tab, I felt TERRIBLE the next morning and had a docs apt that morning . Then my doctor prescibed 2mg Valium 3x daily to relax my muscles, but it didn't help with my anxiety.

I took 4mg (over 8/10 hours) of Valium the day before yesterday, and 6mg (over 8/10 hours) yesterday and 2mg of Valium today around 3pm. I want to get back on the Xanax as I think im in withdrawal from it because I'm feeling worse than ever, having hot sweats and breathing issues (not really breathing issues, but it feels like I am). I also feel dizzy and like..disconnected from everything.

can I take .5mg of Xanax with the Valium still in my system? Basically mixing .5mg Xanax with 2mg Valium (or 8mg if the 6mg is still in my body)?

In general, can one mix Valium and Xanax safely?

I don't drink or smoke and am not really familiar with drugs. I've never really taken any anti-anxiety or other medicine outside of cold medicine before this. I take Lopressor (which is a heart rate/blood pressure reducer) at 25mg every 12 hours.